Robert J. Barro on aggregate demand

There has been a recent kerfluffle over whether Robert Barro rejects the notion of aggregate demand, which he had written with quotation marks as “aggregate demand.”  Scott Sumner surveys the back and forth.

I say use The Google to find out what Barro really thinks and indeed he has written a whole piece on the topic (jstor), namely “The Aggregate-Supply/Aggregate Demand Model,” from the mid 1990s, and here is the abstract:

In recent years, many macroeconomic textbooks at the principles and intermediate levels have adopted the aggregate-supply/aggregate-demand (AS-AD) frame- work [Baumol and Blinder, 1988, Ch. 11; Gordon, 1987, Ch. 6; Lipsey, Steiner, and Purvis, 1984, Ch. 30; Mankiw, 1992, Ch. 11]. The objective was to allow for supply shocks in a Keynesian framework and to generate more satisfactory predictions about the behavior of the price level. The main point of this paper is that the AS-AD model is unsatisfactory and should be abandoned as a teaching tool.

In one version of the aggregate-supply curve, the components of the AS-AD model as usually used are contradictory. An interpretation of the model to eliminate the logical inconsistencies makes it a special case of rational-expectations macro models. In this mode, the model has no Keynesian characteristics and delivers the policy prescriptions that are familiar from the rational-expectations literature.

An alternative version of the aggregate-supply curve leads to what used to be called the complete Keynesian model: the goods market clears but the labor market has chronic excess supply. This model was rejected long ago for good reasons and should not be resurrected now.

If you read the paper, you will see three things.  First, Barro is fully aware of “AD-like” phenomena and does not reject that notion.  Second, Barro seems to prefer the IS-LM model to AS-AD, albeit with some caveats about possible false predictions of IS-LM and also noting in footnote two that he prefers his own presentation in his 1993 text.  Third, Barro’s criticism is (whether you agree or not) that AD-AS collapses too readily into standard rational expectations models and doesn’t really provide an independent foundation for sticky price macroeconomics.  In a nutshell “The AS-AD model is logically flawed as usually presented because its assumption that the price level clears the goods market is inconsistent with the Keynesian underpinnings for the aggregate-demand curve.”

Krugman had written this:

If you read Barro’s piece, what you see is a blithe dismissal of the whole notion that economies can ever suffer from am inadequate level of “aggregate demand” — the scare quotes are his, not mine, meant to suggest that this is a silly, bizarre notion, in conflict with “regular economics.”

I believe that is not a good characterization of Barro’s views and it is also an object lesson in the importance of the Ideological Turing Test.  I would cite not only this piece, but also forty years of journal articles, many of which study the importance of nominal shocks and demand, albeit without (in general) using textbook AD-AS terminology.  Indeed, Barro working with Herschel Grossman is one of the founding fathers of quantity-constrained Keynesian sticky-price macro and he is still citing this work favorably in his mid-1990s piece; see for instance Barro and Grossman (1971, 1974) and also their book from 1976: “This is a textbook on macroeconomic theory that attempts to rework the theory of macroeconomic relations through a re-examination of their microeconomic foundations. In the tradition of Keynes’s General Theory of Employment, Interest and Money…”

On the UI issue, I would note that the multiplier from transfers is likely unimpressive relative to the multiplier from government consumption.


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