Monday, February 24, 2014

My Quiz for Wannabe Keynesians

Simon Wren-Lewis has a great post today on what makes a Keynesian.  Here is my answer together with a quiz for wannabe Keynesians.

First, let me delve into a little highbrow theory.

Figure 1: The Keynesian Cross

Figure 1 is a picture that goes by the name of the Keynesian cross.  On the horizontal axis is income; the value of all wages, rents and profits earned from producing goods and services in a given year.  On the vertical axis is planned expenditure; the value of all spending on goods and services produced in the economy in a given year. Since this is a closed economy, all expenditure is allocated to one of three categories; expenditure on consumption goods, expenditure on investment goods and government purchases.  Since every dollar spent must generate income for someone; in a Keynesian equilibrium, income must equal planned expenditure.

Saturday, February 15, 2014

Faust, Keynes and the DSGE Approach to Macroeconomics

DSGE models have been the subject of much attention recently on the blogs. Simon Wren-Lewis suggests that DSGE modelers made a Faustian bargain and offers a partial defense.  David Glasner is distinctly uneasy with the DSGE approach and although Paul Krugman remains eclectic he wants to retain the IS-LM model as part of his portfolio.

Like it or not, DSGE models are here to stay. I made the following argument in the First Edition of The Macroeconomics of Self-Fulfilling Prophecies in 1993.
In this book I take a point of view that is becoming less controversial but is by no means universally accepted. I will argue that the future of macroeconomics is as a branch of applied general equilibrium theory. 
Believe it or not; twenty one years ago, that was a controversial statement. I argued then that the problem with DSGE models is not the assumption that the economy is in equilibrium. The problem with DSGE models is the implication of some of these models that the equilibrium is optimal. Since then, I have consistently argued that the way forward is to reformulate Keynesian ideas with modern mathematics; that is what the DSGE agenda is all about.

Sunday, February 9, 2014

Keynes and Sticky Prices: Time to Think Outside the Box

Several recent excellent posts have appeared on Keynesian economics and sticky wages and prices. David Glasner points out that
...the sticky-wages explanation for unemployment was exactly the “classical” explanation that Keynes was railing against in the General Theory.
and quoting David again
it’s really quite astonishing — and amusing — to observe that, in the current upside-down world of modern macroeconomics, what differentiates New Classical from New Keynesian macroeconomists is that macroecoomists of the New Classical variety, dismissing wage stickiness as non-existent or empirically unimportant, assume that cyclical fluctuations in employment result from high rates of intertemporal substitution by labor in response to fluctuations in labor productivity, while macroeconomists of the New Keynesian variety argue that it is nominal-wage stickiness that prevents the steep cuts in nominal wages required to maintain employment in the face of exogenous shocks in aggregate demand or supply. 

Monday, February 3, 2014

Rational Expectations and Animal Spirits

Along with the rest of modern macroeconomics, the rational expectations (RE) assumption has gotten quite a bit of flack lately. I don’t think all of it is deserved.  It is not the rational expectations (RE) assumption that is at fault: It is the rational expectations assumption in conjunction with the assumption of a unique equilibrium. 

In standard dynamic stochastic general equilibrium (DSGE) models there is a single rational expectations equilibrium. In the models I work with there are many rational expectations equilibria. Not just one, or two or three: but an infinite dimensional continuum of them. That is not a problem. It is an opportunity that I exploit to model the idea that beliefs matter. In my work, I close my models by adding an equation that I call a 'belief function'. The belief function is an effective way of operationalizing the Old Keynesian assumption of ‘animal spirits’. It is a forecasting rule that explains how people use current information to predict the future. That rule replaces the classical  assumption that the quantity of labor demanded is always equal to the quantity of labor supplied.

You might think that adding a belief function to operationalize animal spirits allows me to dispense with the rational expectations assumption since the belief function could be arbitrary. Not so. Even though we do not live in a stationary environment, our beliefs should be consistent with the outcomes that we would observe in a stationary world.  In such a world, beliefs should obey Abraham Lincoln’s dictum that “you can fool all of the people some of the time or some of the people all of the time but you can’t fool all of the people all of the time.”  In my view, that is the rational expectations assumption.

Download my Data on the Stock Market and Unemployment

The recent drop in the stock market, if it persists, will present serious challenges for the Yellen Fed.

In a couple of recent academic papers, The Stock Market Crash of 2008 caused the Great Recession: Theory and Evidence  here and The Stock Market Crash Really Did Cause the Great Recession here I showed that changes in the value of the stock market cause changes in the unemployment rate three months later. Here is a link to a Freakonomics post that features my work.

I continue to receive requests for the data that I used in those studies. That data is available here. These are important empirical findings that establish a strong and stable relationship between changes in the value of the S&P and changes in the U.S. unemployment rate.