Paul Krugman's Godley-Tobin Lecture

 

Krugman and the editors of ROKE

 

Paul Krugman's lecture, reflecting on the contributions of James Tobin is now published by the Review of Keynesian Economics. The paper can be downloaded here.

The Enduring Relevance of Tobinomics

Krugman's lecture which will be published in the Review of Keynesian Economics (ROKE).

Gatekeepers and herd behavior: On Tooze and the radicalization of Krugman

"But that one is holding the poop!"

Adam Tooze, the author of the monumental Crashed (who was, incidentally,  student of Wynne Godley, one of my mentors), wrote a piece for the London Review of Books that has received a lot of praise. While it reviews Paul Krugman's latest book, it provides an overview of the radicalization of New Keynesians, or at least some, that dominate both in academia, and in the corridors or power. The gatekeepers of knowledge and academic  and intellectual influence, with a close connection to power, so to speak. He tells us at the outset that Krugman, the economist that was a bulwark of free trade, even when the theories for which he received his Sveriges Riksbank Prize (aka the Nobel) suggested that some degree of intervention might be good, and that remained even after the 2008 crisis a defender of the conventional macroeconomic model, not only has moved to the left, but also that "in Joe Biden’s Washington, Krugmanism rules."

This is, however, a misinterpretation of the current situation. Tooze suggests that Krugman is one of the "high-powered centrists inching their way towards seemingly obvious political conclusions." The group includes "three centrists – Biden, Janet Yellen and Jerome Powell [that are] undertaking an experiment in economic policy of historic proportions." And he, also, argues that: "what sets Krugman apart within this cohort is the way he has, since the 1990s, stopped being a gatekeeper of the status quo and instead become its critic. In this respect his closest analogue is Joseph Stiglitz, also once of MIT, a member of the Clinton administration and chief economist to the World Bank. Both men have indisputable standing as members of the elite club of New Keynesians."

I see Krugman as being closer to what Colander, Holt and Rosser referred to as the cutting edge of the profession. The role of cutting edge of the profession, in my reply to them (see the paper in Fred Lee and Marc Lavoie's book here), is to make more reasonable policy propositions, while maintaining the notion that markets do produce efficient outcomes, in spite of the unsurmountable logical problems brought by the capital debates, and that led to the rise of vulgar economics. Krugman in that sense is the epitome of the cutting edge. Of course, in order to make reasonable points he would discard many of his own ideas. But he is no critic of the mainstream. The problem with Tooze's argument lies in there. Krugmanism cannot rule, if he basically had to discard his ideas in order to remain relevant. And relevant here simply means that he can be seen to be on the right side of history, more skeptical of free markets, free trade, and willing to accept significant expansion of deficits and debt.

The ideas that won the day and rule in Biden's America are heterodox ideas, that in fact, until very recently Krugman dismissed as not serious. The possibility of continuous expansion of the welfare state, and the expansion of fiscal deficits and debt were anathema to him. Not only he was against expansionary fiscal policy, but even 'Medicare for All,' the signature proposal of Senator Bernie Sanders, something that is common in all advanced economies, was dismissed as a political nonstarter. And certainly that idea, which is not that radical, has remained in the background, and is unlikely to be pushed by the 'radicalized' Biden administration. Perhaps even Krugman still thinks is far too lefty to be acceptable in the United States.

Biden might be the president, and he has a lot of power about what elements of the agenda to push, and he has certainly moved to the left. No doubt about that. Not surprisingly Heather Boushey and Jared Bernstein, economists with heterodox and labor connections, are defending the fiscal expansion from the Council of Economic Advisers (CEA), while Larry Summers, the quintessential insider of the Clinton and Obama administrations, is criticizing from outside. But the Democratic Party has moved to the left, and the politicians have followed. It is the party of Bernie and Alexandria Ocasio-Cortez (AOC). And the establishment knows they need to move if they want to remain relevant, and have a fighting chance in 2024, since the working class is radicalized, and many will abandon the party if Biden does not deliver.

They are like the French politician that, seeing the masses pass in protest, tells his friends in the café he must leave and follow them, since he is their leader. This is, it goes without saying, more like herd behavior, than leadership. Krugman is, in that sense, the leader of an intellectual sea change about views on the role of the state in the economy.

Tooze may think that these arguments are just the diatribes of those in the left that are angry,* infuriated he argues, with the slow pace of change in the center. The issue is that, even though Krugman is following the herd, he certainly is a central gatekeeper in the economics profession. A profession that has been attacked for good reasons, for its excessive influence in policy, and the recurrent blunders of its luminaries.

Krugman still argues in terms of the conventional model, that he defends, as having done a good job explaining the 2008 crisis. People like Wynne Godley, that truly foresaw the 2008 crisis, often only received the acknowledgement ex-post, sometimes too late, after passing away.** Krugman dismisses heterodox economists as not serious. A type of red-baiting of heterodox economists with significant impact on the ability of the profession to change. He also validates some of worst within the mainstream and is willing to play by their harsh rules.+ This is, of course, because the prestigious teaching positions he held, and still holds, the 'Nobel', that was created to give respectability to certain ideas, the weekly column in the NYTimes are all powerful platforms. The danger in this, in accepting Krugman's narrative that he has been right all along, is to convince ourselves that the profession has indeed changed. Now the dangers of neoliberalism and their main defenders, mainstream economists, are gone. The profession is rehabilitated. But the retreat of neoliberalism is only temporary. Krugman and other gatekeepers will change their tune when the current Keynesian moment passes. If the Bidenomics experiment ends up being of historic proportions, and I do hope it does, although that is still too soon to tell, it will not be a victory of Krugmanism. It will be a victory in spite of it.

* I am not as angry as Paul Romer, though.

** On Krugman critique of Godley's 'hydraulic' model, and my response go here.

+ He famously said: "By the early 1980s it was already common knowledge among people I hung out with that the only way to get non-crazy macroeconomics published was to wrap sensible assumptions about output and employment in something else, something that involved rational expectations and intertemporal stuff and made the paper respectable. And yes, that was conscious knowledge, which shaped the kinds of papers we wrote." [Italics added] See the quote and a discussion of the role of another gatekeeper in France that also won a 'Nobel' here.

Di Bucchianico on Krugman and the Liquidity Trap

New paper on the problems of Krugman and the Liquidity Trap argument (some will be able to download if for free, and I recommend this version; however, there is a previous working paper linked at the bottom for those unable to open).

From the abstract:

Krugman’s ‘liquidity trap’ model constituted a ground-breaking contribution by attributing the long-lasting Japanese stagnation to a negative natural interest rate. Our critique to such a proposal will focus on three aspects. First, we will question the logical structure of the model, providing an alternative interpretation of its closure and arguing that aggregate demand has no crucial role in it. Second, we will argue that a negative natural interest rate can emerge only after a series of overtly restrictive assumptions in a model that does not treat capital and avoids long-run equilibrium analysis. Finally, we will discuss the mainstream literature which followed up until the recent rediscovery of the Secular Stagnation Theory. Within that line of literature, the key features of the ‘liquidity trap’ model continue to occupy a prominent role, thereby letting the critical issues that have been singled out resurface. Our conclusion is that the ‘liquidity trap’ explanation did not provide a satisfying rationale for Japan’s stagnation and cannot describe later economic predicaments either. A comparison with Post-Keynesian models shows their ability to offer insightful policy prescriptions without relying on those shaky theoretical foundations.

Note that an important part of the argument is the critique of the natural rate of interest, something we have done extensively over many years in this blog, and of the notion of a negative one in the context of Summers' discussion of secular stagnation (also done in this blog; see for example here and more recently here in the context of a debate with Stephanie Kelton and MMTers; btw her book is out and anybody wanting to reviewed it for ROKE send me an email; I look forward to reading it too).

The important thing in the paper is that it goes beyond the capital debates critique, and shows the extra restrictions needed for Krugman to get his results, including some interesting thoughts on the problems associated with intertemporal models.

PS: ROKE will soon publish a paper by Serrano, Summa and Garrido Moreira (Fall issue) in which other limitations of the negative natural rate are explored.

PS': Link to working paper here.

MMT and its Discontents: Again (Wonkish and Longish)

Modern Monetary Theory (MMT) has been in the news again, and for good reasons. I actually had a post with the same title back in February of 2012, hence the again in the title. But now, with the irruption of Alexandria Ocasio-Cortez in the political scene ,and with the discussion of a Green New Deal (discussed here 7 years ago) and the feasibility of higher taxes (here, also long ago, among the many on the topic) taking the center of the political debate, MMT has become trendy. The rise of democratic socialist ideas, since Bernie's 2016 campaign, has brought the fiscal feasibility or responsibility, in the more conservative terminology, of such progressive  plans into the center of economic policy debates. Also, the fact that Stephanie Kelton a prominent MMTer is an advisor to Bernie, has brought significantly more attention on their views.

I have discussed Modern Monetary Theory in this blog for years (going back to April 2011, when I first found use of the term, to the most recent earlier this year after Olivier Blanchard American Economic Association presidential address last January), and have known the main MMTers going back to at least the mid-1990s, when I was at the New School and working as research assistant to Wynne Godley at the Levy Institute. I guess, I can be seen, to use the term employed by Doug Henwood in his recent Jacobin piece, as a fellow traveller (like Jamie Galbraith), even though I've been critical of some aspects, in particular when applied to developing countries (more on both Henwood and MMT issues in developing countries below).

There are many critiques, which deal with both theoretical issues, mostly concerned with the Functional Finance aspects of MMT, and with the policy and political effects of MMT advising to the left of center Democratic presidential candidates. Note that I will not try to define MMT precisely, since it is a hybrid of economic theories and policy proposals. I would assume that at core it is composed by the ideas of Chartalist and Endogenous Monetary views, Functional Finance, and an Employer of Last Resort (ELR) program as suggested by Greg Hannsgen in his recent presentation at the Eastern Economic Association (EEA), in sessions we co-organized (with the presence of Randy Wray presenting Stephanie Kelton's slides and Josh Mason; Stephanie was with Bernie at the rally in Brooklyn).

My comments will be, for the most part, directed at issues that fall within the Functional Finance part of MMT, and mostly about developed economies like the US (although, I'll have something to say about developing countries like Argentina or Brazil). I might add that Randy suggested that Functional Finance was a late addition to MMT, since this ideas were not known by MMTers in the mid-1990s or so. I think that the original source for the Functional Finance story was Ed Nell, who organized a conference at the New School back in 1997, I think, with Bob Eisner, and many other Old Keynesians. I had read Abba Lerner and Evsey Domar foundational papers in Ed's classes, and I think his influence on MMTers in this area is reasonable to assume.

Let me start with Paul Krugman's critiques of MMT, which have been clear and perhaps the most widely read (but there are many, including critiques by Tom Palley and Sergio Cesaratto here in the blog). So Krugman, in one of his most recent posts, starts by showing that there are many levels of the fiscal deficits that are compatible with full employment (not sure who thinks that this is wrong; I would add the same is true about the rate of interest, and that there is no natural or neutral rate of interest, a point that Keynes made back in the 1930s, and that is coherent with the capital debates, and, hopefully, it will be clear why this is relevant below). Then he argues more problematically, in my view, that crowding out is a serious concern, in his words: "The question then becomes one of tradeoffs: would the things the government could buy with a higher deficit be worth the lost private investment due to a higher interest rate?" But he knows well that the crowding out effect is empirically (if not theoretically) irrelevant, since investment is not particularly responsive to interest rates (he knows it's all about the accelerator); then he moves to the issue of the natural rate itself.

He seems to think two things (he can certainly correct me if I'm wrong). One, that MMT requires that you use monetary policy in order to achieve full employment. Two, that if you are in a situation of like the zero-lower bound, then the central bank cannot bring you back to full employment. That is, her assume that, using his own graph, the economy would be in position A.

Note that by his own argument you can go back to a point like B, with full employment by pursuing expansionary fiscal policy (be that an ELR or something else like traditional fiscal policy to expand infrastructure spending, for example; on this I should say that Randy suggested that he thinks traditional fiscal policy might be inflationary, and that's something perhaps would be compatible with Krugman; he noted how Minsky suggested that an ELR can be used as a buffer to control inflation). That is the IS would move up.

So it's unclear what the fuss is all about. If it is because the Fed could, in the MMT story (not sure Functional Finance authors would say that), print money to finance the deficits and bring the economy back to full employment, then the concern might be that it would be inflationary, in a Monetarist sense that printing money might be the cause of inflation. But that does not seem to be his preoccupation (I dealt with the issue of monetization of debt back in May 2011 in a reply to Krugman, who was back then, not surprisingly, criticizing MMT). His concern seems to be that the rate of interest would not go up. But of course, there could be a flat interest rate close to zero, a horizontal monetary policy (MP) line, and the expansion of the IS could be achieved bringing the economy to full employment (right below the C and B points with a zero interest rate).

But that doesn't seem to be the issue either. My guess is that he thinks that the problems is more like the one below, from an older post by him, in which the natural rate of interest is negative (my discussion of that here), and the Fed cannot lead the economy to full employment.

So his point is that the Fed cannot make it because it cannot bring the economy to the natural rate of interest, the one that is compatible with full employment and stable prices. He then goes on to criticize Stephanie on her critique of the natural rate, and tells us that: "So what purpose does claiming that the natural rate is a meaningless concept serve? It looks to me like sophistry – word games intended to confuse what should be a simple issue."

I'm not sure what Stephanie said about the natural rate, but I think it is well-established that the natural rate concept is problematic (note that on this some MMTers have said things I would disagree;  e.g. Forstater and Mosler suggest here that the natural rate of interest is zero; my discussion of that here). So I think the position that Krugman attributes to her is correct. Paul Samuelson would agree, as he did when he admitted that the capital debates had shown that neoclassical parables cannot hold (on the capital debates read this old post). So let me explain it briefly. There is no sophistry, just pure logic.

The capital debates show that with factor price reversals, when one good can be said to be capital-intensive at one level of the wage-profit ratio, and labor intensive at another level of the same ratio, there is no monotonic inverse relation between investment and the rate of interest. The investment schedule could look like the one below (my graph), with portions that have a negative slope and some in reverse, and if savings (determined by the level of income as in Keynes' principle of effective demand, rather than a Ramsey inter-temporal model) is given as in the graph below, then there might be no natural rate of interest. Keynes was explicit about that in the General Theory. That means that the monetary authority can set the rate of interest, what Keynes referred to as the normal rate, that was conventional, and that fiscal policy can be used to bring the economy to full employment. Btw, I think that overall Krugman and Kelton agree on that. Krugman says he's defending the theory, not the policy proposals, since he thinks they agree on that.

The point is NOT that the state can do whatever it wants, even though it has a lot of space, but that at the end of the day monetary policy is central for the ability to pursue fiscal policy, and the monetary authority can keep (unless it's forced by law not to do it; and that would bring up the discussion about the rise of the neoliberal idea of independent central banks) interest rates low enough to allow for fiscal expansion without debt growing at a very fast pace. Think of Marriner Eccles during the New Deal (chairman of the Fed at that time; search the blog for more on that). This is the argument that Josh Mason did, in a different way in our session with Randy at the Easterns. Note, also, that even though politically it was acceptable for the Fed to keep interest rates low, at 2.5 percent during the Depression and World War II, by the 1950s political pressures by financial markets and rentiers forced the Fed-Treasury Accord, and things changed (even though rates remained relatively low).

I'll comment briefly on two additional critiques of MMT, the one by Larry Summers, the ex-Treasury Secretary and advisor to the Clintons and Obama, and the one by Doug Henwood, an influential Marxist (see my discussion of his comments, and others, on Marx for the New York Times here), and writer of a very good book on Wall Street. I am sorry to say that both have too many arguments of authority and ad hominem attacks on some MMT authors, which I'm not interested in discussing. But there are a few substantive issues. One is the danger of inflation (that I'm glad Krugman seemed less keen on) and the others are on MMT and developing countries, and the political relevance and practicality of MMT proposals (here most critics have in mind the Bernie/Ocasio agenda of Medicare for all, cheap or free college tuition in public institutions, a jobs guarantee, and a Green New Deal).

I'll start with Henwood. His major issue is inflation, I would say. He says: "That brings us to the next problem: inflation. When the printing presses run freely, it’s not only reactionaries who think that runs the risk of spiraling prices. As I was researching this piece, many people to whom I described MMT, from Democrats to Marxists, brought it up as a worry. MMTers are coy about the topic — they never say how much is too much, and they profess great confidence in their ability to control it." Let me start by saying that inflation has not been a problem in 40 years, while wage stagnation is a central one. But if one is concerned about it, at least one should get the correct analytical tools to discuss it.

He tells us that: "The standard view of the Weimer inflation is that the German economy, severely damaged by World War I and forced to make huge reparations payments to the victors, wasn’t up to the task — it just didn’t have the productive capacity, and its citizens were both unwilling and unable to pay the necessary taxes. So instead the government just printed money and spent it, not only to pay its own bills, but to support bank lending to the private sector." First, that's NOT the standard view of the hyperinflation in Germany. You can read here the standard story, and I cite even a conservative historian like Niall Ferguson admitting that the monetarist story embraced by Henwood is NOT the dominant view among historians. The notion that the economy was at full capacity (didn't have productive capacity) and that printing money caused inflation is what Cagan thought about it. A more refined and somewhat structural story is the dominant view actually. In my view, it is clear that debt in foreign currency (not domestic), and, hence, the external problems of the current account, that forced depreciation, together with wage resistance are at the core of the hyper., German and many others.

In addition, it's worth emphasizing that the US is not Weimar Germany, in the sense that even with much larger fiscal deficits, debt would still be in domestic currency, and no significant pressure for depreciation would arise. The role of the dollar as reserve currency is not really under significant jeopardy. Certainly, there might be questions of inflation if we reach full employment, and that's a different issue (I'll come back to the topic below when I discuss Summers and the political feasibility of MMT sponsored plans). But the kind of alarmism of even suggesting that the US would be on the verge of hyperinflation is not serious. I won't comment on other primary mistakes like the notion that the rise of Nazism is associated to the hyper, when it is clearly connected to the Depression and deflation a decade later.

Henwood is on firmer ground, actually, when he discusses the external limits. Yes, indeed, for most developing countries like Argentina or Brazil, the ability to pursue expansionary fiscal policy is severely limited by the balance of payments constraint. Considerably before full employment, the patterns of consumption and investment may require too many imports, particularly of intermediary and capital goods, and even with capital controls, interest rates might be hiked to avoid capital flight and depreciation. Depreciation does solve the external problem, often by throwing the economy in a recession, and not because it stimulates exports. There is extensive discussion of that in the blog about it. Sometimes MMTers sounded like New Developmentalists in Latin American suggesting that depreciation would solve the external constraint and that capital controls were not even necessary. I don't think Randy believes that (or Stephanie), but it was certainly something that Warren Mosler believed in the past (whether he changed his mind I can't tell). But again the debate seems to be about the feasibility of MMT in the US (that's why I didn't emphasize in my comments on the roundtable the differences of debt in domestic and foreign currency, something I always do, as noted by Josh).

So that leads me to the last critique, the one by Larry Summers in his recent piece in WAPO. Summers says that: "Modern monetary theory... is the supply-side economics of our time" and that "these new ideas [about the importance of fiscal deficits] are being oversimplified and exaggerated by fringe economists who hold them out as offering the proverbial free lunch: the ability of the government to spend more without imposing any burden on anyone." He also says in Monetarist fashion that printing money would lead to hyperinflation. In his words: "As the experience of any number of emerging markets demonstrates, past a certain point, this approach leads to hyperinflation. Indeed, in emerging markets that have practiced modern monetary theory, situations could arise where people could buy two drinks at bars at once to avoid the hourly price increases. As with any tax, there is a limit to the amount of revenue that can be raised via such an inflation tax. If this limit is exceeded, hyperinflation will result." Again, emerging markets, like Germany, borrowed in foreign currency, that they cannot print. It was often the depreciation of the currency, the increase in the prices of imported goods, and the wage resistance of workers that led to hypers, and the central bank printed money afterwards, with money being endogenous. A foreign debt or external problem, not a fiscal one.

But there might be a danger of inflation (not hyper) if Bernie wins the election and manages to pass Medicare for all, free college, a Job Guarantee and actually spend some money on infrastructure, and to do something about global warming, without significant reshuffling of spending. Here is where I think the question of the supposed naïveté  of MMTers comes to play, with Henwood suggesting that they shirk the question of fiscal choices, and with Summers saying they resemble voodoo economics, the supply-side of the left (mind you supply-siders are many things, but certainly not naïve). I think, first of all, that the dangers of inflation are exaggerated, for several reasons. First, the labor market is not as tight as normally suggested. The number of people discouraged and out of the labor force is relatively large. Second, there are positive effects of growth on productivity (the Kaldor-Verdoorn effect, search on the blog too), so the supply constraint is not fixed, rigid at one given level (people said the natural rate of unemployment was 5 percent or higher just a few years back; again check past blog posts). Third, the bargaining power of unions, and workers in general, is not particularly strong, and it would take sometime to pick up.

More importantly, there is no chance that a Bernie presidency (and that's in and of itself a big if) would have both houses and could implement even a little bit of the program presented. Mind you if it happened we would probably get to full employment in a couple of years, and get increases in wages, and perhaps some inflation. But some inflation might be good, in particular if it allows for higher real wages, something sorely needed. How much inflation? Difficult to say, but the structure of the Fed is not going to vanish, and higher rates would be used to discipline the labor class, with the support of many neoliberal Dems. The limit will come probably before full employment and the capacity limit of the economy is reached (yes inflation happens before the capacity limit, because it's often cost push, and the sort of demand pull stuff Summers and Henwood are afraid about is not that common). In other words, the limits to fiscal expansion would be political, not economic, and there is no reason for the left to be up in arms against an imaginary enemy. Hyperinflation is like the the windmills for the Quijote. The giants to attack are actually the ones pointed out in the progressive agenda, like lack of spending on health, education and the environment, and MMTers have been instrumental in getting these ideas in the political discourse, and moving the Dems to the left.

But taxes matter too. Here is where the MMTers refusal to acknowledge that taxes on the wealthy are necessary is a political mistake (not all I've been told, but some for sure, as I've heard that criticism). Note that from the logical point of view they are not incorrect in suggesting that causality goes from spending to taxes, like it goes from investment to savings. It's implicit in the Keynesian/Kaleckian model in which autonomous spending (government spending is in there) determines income through a multiplier process. And taxes, like savings, grow with income. But it is important to note that politically (again this is not analytically, but politically) countries that went for a more ample Welfare State opted to tax their citizens, particularly their more wealthy citizens, at a higher rate. Tax increases on the wealthy should be (and are) part of the progressive agenda. It has an important distributive effect, and it makes the spending politically acceptable. At this juncture, however, even Blanchard says that we should just borrow, since interest rates are low, and will remain low.

The crucial point is that overall MMTers have been helpful in moving the Dems in the right direction (the right direction is to the left), and that is a good thing. The problem with Dems is not the existence of a few social democrats or socialists in their midst. In fact, even being generous there will probably be just three democratic socialists in the presidential primaries (Bernie, and, perhaps, Warren and Tulsi). The problem is the vast majority of neoliberals that still dominate the party. The same could be said about MMT. The problem is not the exaggerated propositions of MMTers, but the excessive fear of inflation when there are too many relevant problems to be concerned with.

Functional Finance, MMT and Blanchard's Presidential Address

So Olivier Blanchard gave the AEA presidential address at the Atlanta meetings earlier this year. If you missed it you can watch it here. The paper is also here. In all fairness, there is nothing new there. He notes the famous rule by Evsey Domar about sustainability of public debt, meaning that if the rate of interest on debt is lower than the rate of growth, debt-to-GDP ratios tend to be stable and you are in no danger in pursuing active fiscal policies.

Note that functional finance is in many ways compatible with Old Neoclassical Synthesis Keynesianism, and it should not be a surprise that New Keynesians accept some of the same arguments. Certainly Domar was an Old Keynesian in that mold, and although he was more difficult to classify, Abba Lerner the founder of functional finance accepted many marginalist arguments.

Blanchard actually is quite conventional and argues that public debt has negative welfare effects and reduces growth (forget this, that the Industrial Revolution was done on a pile, a huge pile, of public debt). He is very clear that he's not in general in favor of more debt, but only under the current circumstances, in which the rate of growth would be above the risk free interest rate of government bonds (that he calls the safe rate) and the marginal efficiency of capital (which really means he thinks in terms of a natural rate, in Wicksellian fashion).

Yet, of course, pundits went crazy. A typical reaction is from Desmond Lachman, and ex-IMF economist (i.e. worked for Blanchard), and fellow at the American Enterprise Institute in the Wall-Street Journal. Two things, one he suggests that Blanchard is a defender of MMT, which is a stretch. MMT involves more than functional finance, like a notion of endogenous and chartal money, and a policy preoccupation with full employment, often embodied in an Employer of Last Resort (ELR) proposal (that's a non exhaustive list). The second issue is that his whole argument is that the rate of interest will go up soon (as a result, presumably of foreign bond holders; in his words: "It’s more likely that investors, particularly from overseas, will demand higher government bond yields to compensate for the elevated inflation or default risk they see from an ever-increasing public debt ratio"). In other words, the foreign crowding-out of the old Mundell-Fleming model.

Of course, the are many problems with this arguments. The Fed has considerably more room than other central banks, and US bonds play a special role in the global economy. The dollar has been relatively appreciated, even with very low rates of interest, and the notion that something has to be done, even with some depreciation, is bogus. Depreciation is neither inflationary, nor contractionary in the US, in contrast to developing countries. The chances of higher inflation, are also subdued, even with the current long, but slow, recovery with low official unemployment. But it says something that there is all this crazy reaction about a very modest defense of fiscal expansion (note also that after Bernie, and AOC, MMT has become synonymous with fiscal expansionism, in ways that Keynesianism was before; naked Keynesianism, you might argue).

PS: If you are interested on the effects of monetization of public debt read this old post that replied to Krugman (who has warmed up to some functional finance/MMT ideas).

On the blogs

The Macroeconomics of Reality-TV Populism -- Krugman mildly critical of Dornbusch's idea of macroeconomic populism, which is good. The problem with redistribution and high wages is not that it produces a crash, at least not because of unsustainable public debt. In the case of Latin America it was always the external accounts. And he is right, it is far from clear that Trump will be a populist in that sense

Keynesian Economics without the Consumption Function -- Roger Farmer wants to get rid of the multiplier, that is, of effective demand. He says that wealth effects matter, not income effects. Beyond the question of whether it's empirically correct, I would say that Keynesian economics without effective demand (the multiplier) is not Keynesian

Festschrifts for Sraffians -- Robert Vienneau lists several books in honor of Sraffian scholars (not sure all in the list are Sraffians though; list is worth looking anyway). He suggests we are in the third generation of Sraffa scholars. Not sure how you count the descent. Mine would be via John Eatwell at the New School, I guess, and he was a student of Joan Robinson, who was a student of Sraffa

On the blogs

Trading Places -- David Warsh on the rise and fall of Keynesianism (i.e. Narayana Kocherlakota) at the Federal Reserve Bank of Minneapolis. A bit old, but worth reading

October Fed Minutes Reinforce New Neutral View -- Richard Clarida on the October minutes, which everybody thinks confirm that rates will rise in December. Minutes are here

The expansionary austerity zombi -- Krugman on why it doesn't go away. Funny thing, it's a New Keynesian invention

On the blogs

The Hamptons Hyperinflation Endorsement -- Paul Krugman on Marco Rubio's endorsement (see also here) by Paul Singer, Vulture Fund owner extraordinaire, and establishment GOP donor

Demand Creates its Own Supply -- Roger Farmer, an uncoventional Keynesian (in my view he defies simple classifications; he remains tied to neoclassical views on the relevance of microfoundations, but does not agree with New Keynesians, or Old Neoclassical Synthesis ones, that wage rigidity is central for Keynesian results)

Keynes never left Canada, and intends to stay -- Simon Wren-Lewis on Nick Rowe's views of Canadian fiscal policy. Not sure about this one, but, at any rate, certainly if you compare the US and Canada with Europe, the former look Keynesian

On the blogs

Imperialism and World War I -- Branko Milanovic, which suggests the usefulness of Marxist theories of Imperialism. There is a nice book on the topic by Anthony Brewer

The workplace Panopticon, or beware of companies whose names end in yze -- A bit older post by David Ruccio on supervision and control of the labor force. Have been teaching David Gordon's Fat and Mean in the Political Economy class, and this is on topic

Economics: What went right -- Paul Krugman again on why conventional macro (New Keynesian style) has done well explaining the crisis (I did comment on this before here, and here)

Beyond Laissez-faire? Seriously?

As I noticed, posting will continue a bit slow for a while. So this is a bit old. Noah Smith suggests that the profession is leaning in a liberal, meaning moderately lefty, direction. He tells us, however, that:

"although there’s a growing consensus that something about U.S. economic policy needs to be changed in a more liberal direction, there isn't any consensus on what. Laissez-faire may have reached the end of its shelf life, but we don’t yet know what is going to replace it."

He praises Reagan-Thatcher's policies for their simplicity. I guess Occam's Razor is the criteria here. Not uncommon, as I noted before, that was Krugman's defense of free trade not long ago. He might be right on the lack of consensus on what to do, even though his minimal program from the discontented seems plausible enough, more fiscal expansion, less free trade agreements, higher wages (start with the minimum) and more regulation of finance.

Note, however, that this policy consensus, is open to a lot of dissensus, and not only on details of policy (e.g. more fiscal expansion where, infrastructure, health, defense? Do we increase the taxes on the wealthy too? And so on). The vast majority of those that now defend these policies do it from an essentially unreconstructed marginalist view (mostly New Keynesians). So the policy defense does not stem from different models (Mankiw, a New Keynesian as much as Krugman and DeLong would not endorse any of these 'left' policies), but from their policy preferences. I would suggest that left leaning economists using mainstream models have a harder time showing that their policy prescriptions are coherent with their theory (they need all kinds of imperfections, and ad hoc assumptions).

But that's not the surprising thing in Noah's piece, at least to me. He's nonchalant about the assumption that the shelf life of laissez-faire policies has somehow expired. It is true that Keynes had suggested that laissez-faire was dead long ago, in 1926. But that proves exactly the policy resilience of laissez-faire. In fact, I would argue that the theoretical persistence of misguided (illogical and lacking evidence) mainstream positions often results from the advantage that these models provide for defending laissez-faire.

So laissez-faire is doing fine. And note that austerity is doing fine, in the US, in Europe, in Latin America, and is still being pushed by the IMF in their actual programs (forget the research department suggesting that sometimes it doesn't work; these views never apply to the real world). FTAs are also doing fine, and pushes for increasing the minimum wage or for more regulation of finance continue to be contested and fought back fiercely. We're far from the end of laissez-faire.

On the blogs

Crowding In and the Paradox of Thrift -- Krugman praises Blanchard and the IMF research department. He too has rediscovered, but it was a few years back in his case, the accelerator. No word from him on why then all IMF policy advice is based on supply side reforms and why Blanchard thinks the priority in the US is fiscal consolidation. My take here. Note that here you have the typical organized hypocrisy story, the research department says reasonable things (accelerator), while the policy advice continues to be the same.

The economist's manifesto -- Tim Harford ask economists for policy advice. Often a terrible idea. Proposals are to abolish national insurance entirely (in my view the worst of all proposals) and replace it with higher rates of income tax, increase property taxes, to spend more on urban development, and R&D and infrastructure. Wren-Lewis proposes a rule for monetization of fiscal deficits when interests rates are at the zero bound. Not too bad.

What Causes Recessions? -- Noah Smith gives the traditional New Keynesian answer, shocks and price rigidities. No mention of endogenous cycles, meaning those that result from the normal functioning of the system. On that go here.

Keynes and the abandonment of the Quantity Theory of Money

I've been reading Peter Temin and David Vines new book Keynes: Useful Economics for the World Economy (see also this). It is a very introductory and conventional reading of Keynes, with the distinctive characteristic that describes the development of Keynes' ideas in the proper historical context. This is good, since Temin is an illustrious economic historian. But he is not a history of economic thought scholar, and that has important implications in this case.

If there is any doubt about the conventional reading of Keynes, one is reminded by them that Keynes theoretical innovation is that: "he abandoned the assumption that prices are flexible which had been made by almost all previous economists—including by him in his Treatise on Money—for the more appropriate assumption for the 1930s: sticky prices.” No notice that the whole chapter 19 of the General Theory (GT) is about wage and price flexibility to show that it does not solve the unemployment problem, and it actually makes it worse.

But that is not the the main problem with the book. That is, in fact, the common reading among both Old and New Keynesians, with the latter providing microfoundations for rigidities. The authors claim that: “in order to free the analysis from the assumption of full employment, Keynes had to free himself from the Quantity Theory too.” Actually that is incorrect, since one can have endogenous money, and abandon the Quantity Theory of Money (QTM), without getting rid of Say's Law, or the neoclassical version of it which implies full employment, as indeed Keynes had done in the Treatise on Money (TM), his Wicksellian book.

The view of the Keynesian Revolution as a movement from price flexibility to price rigidity is well documented, and even if it has no basis in Keynes, it might acceptable to some authors. Krugman, who is not a historian of thought, explicitly says he does not care what Keynes actually said, for example. Note that saying that Keynesian policies are necessary as a result of price rigidities is not the same that saying that Keynes actually said that. And for historians of economic thought the difference is important.

More problematic is the idea of the Keynesian Revolution as a movement away from the QTM. There is a lot of scholarship in this direction, including some from Keynes' own disciples, like Richard Kahn in his The Making of the Keynesian Revolution. Actually in the GT Keynes goes back to an exogenous money approach, and in that sense is closer to the QTM than in the TM, which had endogenous money. The important thing in the GT is that Keynes noted that the natural rate of interest in his TM should be abandoned. That is, the idea that the interest rate brings investment into equilibrium with full employment savings had to be substituted by the notion of changes in income bringing savings into equilibrium with autonomous investment. The theory of interest or monetary theory comes later as a result of the abandonment of the Loanable Funds Theory. This is not to say that the abandonment of the Quantity Theory of Money is not important, but clearly it is not sufficient to lead to a theory of effective demand. 

The book also tries to show that there is a continuity in thinking between The Economic Consequences of the Peace and the discussions about the reorganization of the world economy at Bretton Woods. This is hard to defend, in particular since the book itself shows that Keynes' theoretical views changed as a result of the economic policy events, like the return to the Gold Standard at the pre-war parity, and the Great Depression. One of the important things about Keynes is exactly that, as stated in the phrase often attributed to him, when he was proven wrong, he changed his mind.

On being a 'real Keynesian'

1965: when we were all Keynesians (wink, wink, nudge, nudge, say no more)

Recently the Boston Globe had a piece on the Leontief Prize shared by Duncan and Lance, but emphasizing to some extent that while the winners are true heterodox economists (for a personal definition of heterodox go here) and 'real Keynesians' one would think, some well known progressive economists, like Krugman, are not 'real Keynesians.' In many ways, the issue has been discussed here before (or here).

Keynesian is one of those labels that is imbued with several meanings, and there are, not surprisingly, many prefixes to denote the particular Keynesian tribe, e.g. neo-Keynesian, post-Keynesian, New Keynesian, Old (Neoclassical Synthesis) Keynesian, sometimes referred in less polite fashion as Bastard Keynesian, classical-Keynesian (Sraffian-Keynesian?), etc. And those are just the ones related to theory, since policies have been referred to as Military Keynesianism or more recently weaponized Keynesianism, Social Democratic Keynesianism, Pragmatic Keynesianism, and even Republican Keynesianism. I've been told that Naked Keynesianism is a thing. Semantic saturation may imply that the very meaning of Keynesian is too vague to have any clear connotation. Plain Keynesianism is an avis rara.[1]

One way in which Keynesianism is understood is related to its policy implications. The notion that fiscal expansion might be needed to get out of a recession. An idea not discussed in the GT, beyond some vague reference to the socialization of investment. In that sense, there is little doubt that Krugman, and others like him (e.g. Brad DeLong, Simon Wren-Lewis if we stick to those with prominent blogs) are Keynesians. New Keynesians are for fiscal expansion in the particular situation of the zero bound interest rate, in which monetary expansion cannot be pursued. And they have been consistently against austerity policies in the US and in Europe, and political allies of many radical or heterodox Keynesians.

But if policy is the yardstick of Keynesianism, then one must remember that Keynes supposedly argued in the 1944, after a famous Washington meeting with many Keynesian economists in DC, that he was not a Keynesian.[2] Meaning he was not for further stimulus after the war, presumably because unemployment was not going to be a problem. In the same vein, many heterodox Keynesians are often for contractionary policies, including in situations in which the economy is far from full employment. Lance defended in the QA session after the prize that Brazil might need fiscal adjustment since it has an external problem.[3] These would be anti-Keynesian views, if the fiscal expansion policy proposition is the true meaning of Keynesianism.

But obviously the policy perspective, as important as it is, is only a narrow definition of the meaning of Keynesianism. The essential point that Keynes was trying to prove was that, even with price flexibility, the economic system does not have a tendency to the natural rate of unemployment (or the level of full employment, associated with price stability). He was even very clear that the very notion of a natural rate -- Keynes actually referred to the analogous natural rate of interest rather than the unemployment one, which was only discussed by Friedman in the late 1960s -- was a bad idea. By that measure, Keynes himself failed, since the acceptance of the marginalist investment theory, with investment inversely related to the rate of interest, implied that there was a sufficiently low rate of interest that would bring investment to equilibrium with full employment savings. However, once one gets rid of the neoclassical theory of investment, the possibility of persistent unemployment, of unemployment equilibrium (not disequilibrium) is perfectly possible. The system is inefficient and the cause is not an imperfection.[4]

Note that by this definition Keynes himself failed to provide a full explanation of why the system does not tend to full employment, since the notion of a natural rate was still part of his model. In this theoretical sense, Keynesian ideas had to be fully developed later in order to get to the 'real Keynesian' notion of unemployment equilibrium. An many heterodox Keynesians still fail to get that point. Uncertainty, which is often referred as one of the reasons for persistent unemployment, per se is not a cause for the system not going to full employment. It's just another imperfection. In this case, the group of economists that are 'real Keynesians' is narrow indeed. And it  shouldn't be a surprise that many economists that think of themselves as heterodox do like Say's Law, at least in the long run.[5]

I must emphasize that the fact that the number of economists that understand effective demand is very narrow (and even narrower if you add those that get the old classical political economy theory of value and distribution; are we counting 'real Marxists' too?), and that theoretical confusion and error are widespread is not new. The profession was always dominated by a vague and somewhat incoherent defense of the free market forces. Most Ricardian economists were not 'real Ricardians' and to this day readers of Adam Smith miss the point.[6] The combination of factors that allowed for the Keynesian policy consensus between the Depression and the collapse of Bretton Woods were peculiar, and involved not only the fear that capitalism would collapse, but also the existence of an alternative system.

In one sense, I do agree with the message of the Boston Globe piece. The theoretical definition of Keynesianism takes precedence and is more relevant. Without a solid theoretical result, alternative to the mainstream, there is no basis for an alternative policy prescription. Imperfections may allow for Keynesian policies, but they may also suggest that the solution is neoliberal policies of eliminating imperfections (e.g. rigidities in the labor market). 'Real Keynesians' are truly important. On the other hand, it is important to notice that in the age of austerity, the policy dimension of Keynesianism becomes more relevant.

So I'm increasingly favorable to the Keynesians, that might not be 'real' (heterodox), but that promote Keynesian policies. We need more of those around, even if they are not 'real.' Particularly in government positions. For example, the Keynesian economists in the Kennedy-Johnson administration were certainly not heterodox, and their view of the space for Keynesian policies was built on the notion of rigid wages, and a stable Phillips Curve. All very problematic from a theoretical point of view. But they did the tax cut, the war on poverty and Medicaid/Medicare programs. With enemies like these who needs friends?

[1] Wynne Godley used to say that he was just Keynesian. No prefix.

[2] I'm exaggerating a bit. In the meeting he argued against Abba Lerner's functional finance, even though later he suggested he liked the book in which Lerner's ideas were fully developed. There are many accounts of that meeting, and not all consistent. In one of these, Evsey Domar, who was seating next to Lerner supposedly said to Lerner regarding Keynes non endorsement of expansionary policies that: "he ought to read The General Theory." The implication is that Keynes was not a Keynesian, at least not under all circumstances.

[3] This view has been defended by many economists that are certainly not neoclassical. Some New Developmental economists suggest that fiscal austerity to control inflation, and depreciation to promote growth are required in the current circumstances in Brazil. A similar view is held by some, arguably heterodox, economists in Argentina and Mexico too. I have discussed extensively before why I think this is a misguided policy (e.g. here or here).

[4] Hence the relevance of the capital debates. Keynes suggestion that the system did not have a tendency to full employment in chapter 19 of the GT, and his arguments there are based on the effects of lower wages and prices on income distribution and on debt. These arguments suggest that the natural (full employment) rate might be a weak attractor of the system. The capital debates eliminate the existence of the full employment rate as an attractor.

[5] And it's not just the heterodox that are often confused, and provide only partial and incomplete critiques of the mainstream. That's even more common among the mainstream. It's particularly true of the younger generation of mainstream economists. Most neoclassical economists do not understand neoclassical economics. I would suggest that reading Piketty gives you a sense of how little neoclassical economists understand neoclassical theory. The same would happen, for example, if one reads Noah Smith's blog. On this go here.

[6] Brad DeLong dismisses Marx because he embraced the labor theory of value (LTV), but sings the praises of Adam Smith, as if he didn't also use the LTV. See here.

Krugman is not a real Keynesian

From The Boston Globe:

Keynes’s insights have enormous practical importance, according to Lance Taylor and Duncan Foley of the New School. Temperamentally opposite — Foley a brilliant theorist, Taylor a pragmatist influential in developing nations — they jointly received the Leontief Prize for Advancing the Frontiers of Economic Thought at Tufts University’s Global Development and Environment Institute on Monday. But isn’t Keynes now mainstream? No, say Foley and Taylor. The mainstream still sees economies as inherently moving to an optimal equilibrium, as Wicksell did. It still says demand causes short-run fluctuations, but only supply factors, such as the capital stock and technology, can affect long-run growth.

Read rest here. Not a surprise for the readers of this blog.

Teaching macroeconomics: the resilience of the ISLM model

Teaching ISLM this and next week. I have posted in the past on this, so I'll just put the links below to the relevant posts.

ISLM: What is it good for?

ISLM: a further explanation and a defense

Krugman is actually right on ISLM and Minsky

There are more posts that deal with some relevant issues that you can access if you click on the ISLM label below.

The interesting thing is that, although the ISLM is less used in theory, in particular because the multiplier story at the core of the IS has been substituted by a Ramsey intertemporal maximization story and the LM has been substituted by a Wicksellian interest rate rule, it is still the workhorse of macroeconomic teaching, and likely of simple policy thinking. In many ways the ISLM remains a much better basis for thinking about the economy than modern New Keynesian DSGE models (if nothing else because of the multiplier).

The rise of vulgar economics and the end of dissent

Funny thing, the rise of vulgar economics, which I discussed before (here, here, and here; see also this and this papers for more on the topic) didn't just lead to the ostracism of heterodox approaches to economics. It also led to a significant decrease in the debate within the mainstream. Or at least is what the figure below, from the interesting blog post by Joe Francis, seems to indicate. At some point in the 1960s, more than 20% of the papers in the main journals were a reply, a comment or a rejoinder to the work of someone else. Not anymore.

It is clear that the Great Depression and the Keynesian Revolution seemed to increase debate within the mainstream, and that, as Joe says, the: "decline in debate... appears to have been associated with the emergence of a ‘neoliberal’ hegemony from the 1970s onwards." That's essentially correct.

And the decline in debate explains why Lucas could say in the early 1980s that: "at research seminars, people don't take Keynesian theorizing seriously anymore; the audience starts to whisper and giggle to one another." And also why if you wanted to publish you basically had to accept the crazy New Classical models. Krugman admitted to that before, as I've already noticed. He argued that: “the only way to get non-crazy macroeconomics published was to wrap sensible assumptions about output and employment in something else, something that involved rational expectations and intertemporal stuff and made the paper respectable.” You must remember, you don't publish, you don't get tenure. So crazy models became the norm.

Not only heterodox economists were kicked out of mainstream departments, and had to create their own journals in the 1970s, but also the pressure within the mainstream to conform and silence dissent was strong indeed. Note that many, like Blanchard and Woodford for example, in the mainstream continue to suggest that there is a lot of consensus between New Keynesians, and Real Business Cycles types. In fact, they say there is more agreement now than in the 1970s. How is the consensus methodology in macroeconomics, you ask. From Blanchard's paper above:

"To caricature, but only slightly: A macroeconomic article today often follows strict, haiku-like, rules: It starts from a general equilibrium structure, in which individuals maximize the expected present value of utility, firms maximize their value, and markets clear. Then, it introduces a twist, be it an imperfection or the closing of a particular set of markets, and works out the general equilibrium implications. It then performs a numerical simulation, based on calibration, showing that the model performs well. It ends with a welfare assessment."

And yes that is also the basis of New Keynesian models. The haiku basically describes the crazy models in which reasonable results must be disguised if you're to be taken seriously in academia. When everybody agrees, there is little need for debate. And you get stuck with crazy models. The lack of debate within the mainstream to this day is also, in part, what provides support for austerity policies around the globe, even when it is clear that they have failed.

Is Krugman open to debate?

So I used to post some comments on Krugman's blog, but over the last few years when I post something in it doesn't get published. The Kman likes conversation, provided nobody calls him up on his bs. So in his critique of heterodox economists he said:

"So if you [presumably heterodox economist] go around claiming that model-oriented, quantitative economics gave rise to austerity mania, you’re getting the story all wrong. Worse, you are in effect covering up for the austerians’ intellectual sins."

My comment was:

"Have the courage to publish my comments (which have been banned for years now). If you claim to be a serious person open to debate. Seriously, heterodoxy is NOT about model-oriented, quantitative economics giving rise to austerity. It is about a model that against logic and evidence suggests that the market returns to its natural rate unless there are imperfections. And in that sense, even New Keynesian like you that defend more fiscal stimulus miss the point."

Let's see if he publishes it.* Note that my point is that there are plenty of formalizations of heterodox economics [not all the same; my preferences are well known for readers of the blog, namely: effective demand in the long run with some sort of supermultiplier]. There are some heterodox authors against formalization, but also some neoclassicals (some Austrians, in particular). But the main differences between heterodox and orthodox economists are about causality and NOT about formalization. On debate and monologue in economics see this.

PS: If you want a formalized growth model as an example go here. For one on inflation here.

* Update: Shaming does work. It was published.

On the blogs

‘What are economists for? To make people laugh’: vale, Charlie Hebdo’s Bernard Maris -- Steve Kates on the late Bernard Maris, a post-Keynesian economist and victim of the attack on Charlie Hebdo

Unemployment and Productivity Growth -- JW Mason on productivity growth and Verdoorn's Law among other things

Secular stagnation: a neo-paleo-Keynesian perspective -- Roger Farmer on secular stagnation, Larry Summers' style, and neo-paleo-Keynesian economics (wow, is that a thing now?!)

Orthodoxy, Heterodoxy, and Ideology -- Krugman on orthodoxy and heterodoxy (as always he discusses something else, distorting the meaning of heterodox as being against formalization, and not the acceptance by the mainstream of the natural rate hypothesis and the need for imperfections; this was discussed here before and in many other posts)

Some thoughts on currency crises and overshooting

So I've been teaching an international finance class, after a long while I might add. The discussion of currency crises models I think is interesting, since it is very revealing of the mainstream assumptions about the long run. Typical discussion would imply that in the long run the Quantity Theory of Money (QTM) and Purchasing Power Parity (PPP) hold. PPP means simply that the exchange rate adjusts for differences between the domestic and foreign price levels. Hence, we have that S =P/P*, where the star indicates foreign variable. If in addition we believe with the QTM that the central bank (CB) controls prices by controlling the money supply, then the CB can control the exchange rate indirectly.

In the figure below the 45o line shows the equilibrium levels of the exchange rate (S) as the price level, which is related to the money supply. Now suppose that the central bank fixes the exchange rate at S1 (the graph is based on Dornbusch representation in his classic paper; for now disregard the QQ curve). If the money supply is below the level that corresponds to P1, then the fixed exchange rate is too depreciated for the current stock of money, stimulating exports, discouraging imports, and leading to Current Account (CA) surpluses. In this case, the central bank would accumulate international reserves. The accumulation of reserves leads to increasing money supply and the economy moves to a new equilibrium.

If the central bank follows the rules of the game and it is credible (and the assumptions are also valid, meaning the economy has a tendency to full employment and increase in money supply only affect prices) then the money supply increases/decreases with the CA surpluses/deficits and the system converges to a stable equilibrium. However, if the commitment to the fixed-peg is not credible, and the rules of the game are not followed, then problems might arise. Imagine a situation in which the monetary authority continues to print money, to finance fiscal deficits for example, and the fixed exchange rate would now be below its equilibrium value (below the 45o line). Beyond the equilibrium point the central bank would start losing reserves. At some point, say when the money supply reaches the money supply level compatible with P2, the stock of reserves would be depleted. At this point, the central bank cannot defend the exchange rate anymore and the exchange rate jumps to S2. The Krugman model basically assumed exactly this, with the difference that if agents have rational expectations (perfect foresight in this case), then they would have an advantage to try to speculate against the currency before reserves are exhausted.*

In the model above the currency crisis occurs because the CB does not follow a monetary policy consistent with the fundamentals, that is, prints too much money to finance the government. Although, not immediatly obvious the model above is a simplified version of the Mundell-Fleming (MF) model, in the long run, when prices rather than income is the adjusting variable.In this case, the MF model can be represented with the exchange rate and prices, rather than output, as the adjusting variables. The QQ curve is a downward sloping curve, since higher prices increase money demand (or reduce the real money supply), leading to a higher rate of interest and a more appreciated exchange rate (lower S). Note the QQ curve is just the old LM for an open economy.

Also, because the QTM and PPP hold it must be true that increases in money supply lead to higher prices which lead to a proportional change in the nominal exchange rate, for a given foreign price and foreign money supply. In other words, the 45o degree line which corresponds to the proportional changes in domestic prices and the nominal exchange rate must still hold. We can derive the IS curve too, which would be upward sloping, but it is unnecessary, since if PPP holds then the economy must be in the long run on the 45o degree line.**

Dornbusch's trick, which was considered the first New Keynesian model (featuring both rational expectations and price rigidities), is that the nominal exchange rates adjusts faster than prices, then an increase in money supply would shift the QQ (LM) curve upwards. An increase in money supply reduces the domestic interest rate, leading to a depreciation of the currency. The economy moves from point A to point B. Then as depreciation increases net exports, and a lower rate of interest leads to more investment, there will be excess demand in the goods market, and for an economy that is at full employment, prices would go up. As prices go up, then the economy moves down the new QQ’ curve from point B to C, since with higher prices money demand increases and the rate of interest must increase (less than the initial decrease) causing some appreciation (less than the initial depreciation). At the new equilibrium the exchange rate is more depreciated than at the original equilibrium, but because of the short run rigidity of prices, the exchange rate overshoots its equilibrium value in the short-run. The point was that even if markets were efficient, in the sense that with price flexibility they tend to full employment and to the equilibrium exchange rate (PPP), the use of the exchange rate to deal with shocks might lead to excessive volatility.

There are many problems with the long run MF model (meaning the one solved in the S-P space). The obvious one is the notion that price flexibility leads to full employment, something that Keynes long ago suggested was NOT the case. Although Keynes was aware of the possibility of the system returning to full employment with price flexibility, he suggested that if lower prices had a negative impact on firms that are indebted, then investment would fall. In his own words: "indeed if the fall of wages and prices goes far, the embarrassment of those entrepreneurs who are heavily indebted may soon reach the point of insolvency, — with severely adverse effects on investment." In other words, with price flexibility the IS shifts back, and there is no tendency to full employment. That means that one should stick with the solution of the model in S-Y space, if one wants to introduce the open economy (one such model, without full employment and many other mainstream characteristics is available here).

Alternative (classical-Keynesian, post-Keynesian or whatever you prefer to call them) models would not only emphasize the role of quantity adjustments, but also the the sustainability of the current account (CA), rather than fiscal deficits in the explanation of currency crises. While conventional currency crises models of all generations (including the more heterogeneous 3rd generation models) suggest that at the heart of currency crisis there is a fiscal crisis, post-Keynesians emphasize terms of trade shocks and hikes to foreign rates of interest, highlighting the role of the balance of payments constraint in currency crises. Note that the economy in this view is not at full employment, and, hence the effect of fiscal expansions is not on prices, but on the level of activity. Higher level of income leads to increasing imports and a deteriorating CA. It’s the deteriorating CA and not the fiscal deficits that matter and the CA position might worsen even if the fiscal accounts are balanced. Further, after a currency crisis the central bank hikes the rate of interest, increasing the costs of debt-servicing, and, hence, government spending, at the same time that the recession reduces the revenue, leading to a weakening of the fiscal accounts. In this case, it is the external currency crisis that causes the domestic fiscal crisis. Causality is reversed. My two cents.

* Later models, like Obstfeld's, shown that if the costs of defending the parity are high, for example because in order to preclude the loss of reserves associated with a currency attack, the central bank hikes the rate of interest and pushes the economy into a recession, then there is a chance that self-fulfilling speculation might lead to a crisis.

** The IS curve would be positively sloped and steeper than a 45o line, since depreciation creates excess demand in the goods market. To restore equilibrium, domestic prices would have to increase, though proportionately less, since an increase in domestic prices affects aggregate demand, both via the relative price effect and via higher interest rates.

PS: I had posted before on my course here, were there is a link to Serrano and Summa's critique of the MF model.