Yes, The Cambridge Capital Controversies Do Matter

From Unlearning Economics:

I rarely (never) post based solely on a quick thought or quote, but this just struck me as too good not to highlight. It’s from a book called ‘Capital as Power’ by Jonathan Nitzan and Shimshon Bichler, which challenges both the neoclassical and Marxian conceptions of capital, and is freely available online. The passage in question pertains to the way neoclassical economics has dealt with the problems highlighted during the well documented Cambridge Capital Controversies:

The first and most common solution has been to gloss the problem over – or, better still, to ignore it altogether. And as Robinson (1971) predicted and Hodgson (1997) confirmed, so far this solution seems to be working. Most economics textbooks, including the endless editions of Samuelson, Inc., continue to ‘measure’ capital as if the Cambridge Controversy had never happened, helping keep the majority of economists – teachers and students – blissfully unaware of the whole debacle.

A second, more subtle method has been to argue that the problem of quantifying capital, although serious in principle, has limited practical importance (Ferguson 1969). However, given the excessively unrealistic if not impossible assumptions of neoclassical theory, resting its defence on real-world relevance seems somewhat audacious.

The second point is something I independently noticed: appealing to practicality when it suits the modeller, but insisting it doesn’t matter elsewhere. If there is solid evidence that reswitching isn’t important, that’s fine, but then we should also take on board that agents don’t optimise, markets don’t clear, expectations aren’t rational, etc. etc. If we do that, pretty soon the assumptions all fall away and not much is left.

However, it’s the authors’ third point that really hits home:

The third and probably most sophisticated response has been to embrace disaggregate general equilibrium models. The latter models try to describe – conceptually, that is – every aspect of the economic system, down to the smallest detail. The production function in such models separately specifies each individual input, however tiny, so the need to aggregate capital goods into capital does not arise in the first place.

General equilibrium models have serious theoretical and empirical weaknesses whose details have attracted much attention. Their most important problem, though, comes not from what they try to explain, but from what they ignore, namely capital. Their emphasis on disaggregation, regardless of its epistemological feasibility, is an ontological fallacy. The social process takes place not at the level of atoms or strings, but of social institutions and organizations. And so, although the ‘shell’ called capital may or may not consist of individual physical inputs, its existence and significance as the central social aggregate of capitalism is hardly in doubt. By ignoring this pivotal concept, general equilibrium theory turns itself into a hollow formality.

In essence, neoclassical economics dealt with its inability to model capital by…eschewing any analysis of capital. However, the theoretical importance of capital for understanding capitalism (duh) means that this has turned neoclassical ‘theory’ into a highly inadequate took for doing what theory is supposed to do, which is to further our understanding.

Apparently, if you keep evading logical, methodological and empirical problems, it catches up with you! Who knew?

Felipe & McCombie: The Aggregate Production Function And The Measurement Of Technical Change

 

In a recent post, see here, it was explicated that TFP only leads to confusion in mainstream analysis of economic growth. Jesus Felipe & John S.L. McCombie's new book provides an invaluable extensive analysis of the issue at hand. 

Felipe and McCombie have gathered all of the compelling arguments denying the existence of aggregate production functions and showing that econometric estimates based on these fail to measure what they purport to quantify: they are artefacts. Their critique, which ought to be read by any economist doing empirical work, is destructive of nearly all that is important to mainstream economics: NAIRU and potential output measures, measures of wage elasticities, of output elasticities and of total factor productivity growth. – Marc Lavoie, University of Ottawa, Canada

See here

So? None of your conclusions follow from your arguments

Krugman has a post on the effects of technological change on employment. Here is a very illustrative case of the limitations of mainstream marginalist (neoclassical) economics, which leads a reasonable and intelligent economist to all sorts of mistakes. He says:

"start with the notion of an aggregate production function, which relates economy-wide output to economy-wide inputs of capital and labor. Yes, that sort of aggregation does violence to the complexity of reality. So?"

Implicit here is the incorrect notion that the problem with the aggregate production function is over-simplification. Nope, that is a feature of all theories of course. The problem is far worse; it is that it leads to logical mistakes.* So, as we will see, none of Krugman's conclusions follow from his analysis, and that is kind of a problem. Lack of logical coherence and empirical evidence are after all the two main criteria of demarcation between scientific knowledge and the half-baked notions of ideologues.

His first point, which is based on the marginalist theory of distribution**, is that:

"in competitive economy ..., we would expect the labor force to achieve full employment by accepting whatever real wage is consistent with said full employment."

In other words, wage flexibility guarantees the full utilization of labor. A reduction in the real wage in the case of unemployment would lead to full employment (yes, he actually does not defend this in policy discussions, because he thinks that nominal wage rigidities preclude adjustment; mind you his real preocupation is that the rate of interest of equilibrium is negative, precluding adjustment in capital markets).

Of course this is nonsense. A reduction in real wages, and I'm not even talking about the effects of deflation on demand which were discussed by Keynes in the chapter 19 of the General Theory, may not lead to an increase in the demand for labor. First, it must be noted that if wages go down, since wages are part of the cost of production of produced means of production (i.e. capital), the price of the latter also goes down. There is a priori no reason to say that firms will substitute labor for capital (on capital debates go here; really Krugman should read this stuff).

Second, once the idea that the intensity of the use of a 'factor of production' is inversely related with its remuneration is abandoned (by the way there is no evidence for the notion that real wages are inversely related to employment utilization, in fact, if anything, the evidence points in the other direction, with real wages being slightly pro-cyclical), there is no reason to believe that real wages are connected to productivity (and again there is no evidence for that relation either, which means that when Krugman asks "what is that real wage?" and replies that it is "the marginal product of labor at that point," he is also incorrect). Yes real wages have stagnated, since the bargaining power of the working class has deteriorated, with productivity still growing since the 1970s.

So, what is the problem Mr. Krugman? That your conclusion, that the effects of technical change on employment are ambiguous, does not follow logically from your arguments. Ricardo's discussion of the effects of technical change on employment, in his famous chapter on machinery, is far more interesting and coherent than Krugman's (see the paper here). Not just the idea of a natural rate has to be abandoned, but the essential principle of substitution, which allows for the natural rate, must be dropped too. Logical coherence and evidence require it.

* For a serious discussion of the limitations of the aggregate production function go this paper by Jesus Felipe and Franklin Fisher here.

** The quote of Hicks classic presentation of the marginalist theory of wages leaves little doubt of where Krugman stands, if you had any.