'cause it has no implications...
In a previous post, Anonymous commented: "Brad DeLong has been posting slides from one of his classes going over supply and demand (and quotas and price ceilings, market equilibrium, etc.) on his blog. They're pretty entertaining and filled with pop-cultural references. I was wondering what a Post-Keynesian perspective on them might be."
I promised to check Brad's posts and provide a short answer. So here it is. In fact, this semester I am teaching an intro course, something I haven't done since my time in Kalamazoo College. This is not a regular course for me to teach, in other words, like say intermediate macro. At Bucknell all intro courses provide more than the neoclassical (marginalist) perspective. While Brad starts with a neoclassical version of supply and demand (see here) on the basis of Krugman's intro textbook, we start with history and history of ideas, based on a discussion of the classical authors and Marx (here, here and here) and only then get to the supply and demand approach (here). In fact, I am also using Krugman's textbook, together with Heilbronner and Milberg's The Making of Economic Society and additional readings.
In other words, while there is a need to teach the basics of what the mainstream of the profession thinks it is relevant, it is also important to provide critical alternatives to the mainstream. The liberal arts education in the US allows for a lot of flexibility and for the introduction of alternative perspectives. The textbooks (almost all neoclassical) tend to fudge the fact that the notion that economics is about rational choices of individuals faced with scarcity is relatively new (the Marginalist Revolution of the 1870s)*, and quite different from the old classical (or surplus approach) tradition of the material reproduction of society.
* Interestingly enough, in the US the profession was not dominated by neoclassical economics until the 1930s and 1940s, when the rise of Keynesian economics, in the Neoclassical Synthesis version, brought it to the forefront of research, teaching and policy influence. Samuelson's 1948 Economics, the forerunner of all mainstream textbooks, did probably more than any other book to make neoclassical economics the dominant view. Before that the profession in the US was dominated by a potpourri of eclectic and institutionalists authors that held the main teaching positions and were at the head of key institutions like the American Economic Association and the National Bureau of Economic Research (NBER).