AIL Theory and the Ailing Phillips Curve: A Contract Based Approach to Aggregate Supply

This paper presents empirical evidence from U.S. data of a structurally stable aggregate supply relationship between real and nominal rates of interest and the rate of unemployment. The paper reviews theories of contracts that are based on the twin assumptions of asymmetric information and limited collateral and it argues that these theories (referred to as A.I.L. theories) provide a strong theoretical foundation for a contract-based theory of aggregate supply. It is suggested that the original Phillips curve estimates should be reinterpreted in the light of A.I.L. theories which represent alternatives to the Phelps-Friedman interpretation of the Phillips relationship.

The Stock Market Crash of 2008 Caused the Great Recession: Theory and Evidence

This paper argues that the stock market crash of 2008, triggered by a collapse in house prices, caused the Great Recession. The paper has three parts. First, it provides evidence of a high correlation between the value of the stock market and the unemployment rate in U.S. data since 1929. Second, it compares a new model of the economy developed in recent papers and books by Farmer, with a classical model and with a textbook Keynesian approach. Third, it provides evidence that fiscal stimulus will not permanently restore full employment. In Farmer’s model, as in the Keynesian model, employment is demand determined. But aggregate demand depends on wealth, not on income.

Shooting the Auctioneer

Unemployment Real Business Cycles

Aggregate Demand and Supply

This paper is part of a broader project that provides a microfoundation to the General Theory of J.M. Keynes. I call this project 'old Keynesian economics' to distinguish it from new-Keynesian economics, a theory that is based on the idea that to make sense of Keynes we must assume that prices are sticky. I describe a multi-good model in which I interpret the definitions of aggregate demand and supply found in the General Theory through the lens of a search theory of the labor market. I argue that Keynes' aggregate supply curve can be interpreted as the aggregate of a set of first order conditions for the optimal choice of labor and, using this interpretation, I reintroduce a diagram that was central to the textbook teaching of Keynesian economics in the immediate post-war period.

A sunspot-based theory of unconventional monetary policy

This paper is about the effectiveness of qualitative easing, a form of unconventional monetary policy that changes the risk composition of the central bank balance sheet. We construct a general equilibrium model where agents have rational expectations, and there is a complete set of financial securities, but where some agents are unable to participate in financial markets. We show that a change in the risk composition of the central bank’s balance sheet affects equilibrium asset prices and economic activity. We prove that, in our model, a policy in which the central bank stabilizes non-fundamental fluctuations in the stock market is self-financing and leads to a Pareto efficient outcome

On the indeterminacy of determinacy and indeterminacy

A number of authors have attempted to test whether the U.S. economy is in a determinate or an indeterminate equilibrium. We argue that to answer this question, one must impose a priori restrictions on lag length that cannot be tested. We provide examples of two economic models. Model 1 displays an indeterminate equilibrium, driven by sunspots. Model 2 displays a determinate equilibrium driven by fundamentals. Given assumptions about the shock distribution of model 2, it is possible to find a distribution of sunspot shocks that drive model 1 such that the two models are observationally equivalent. JEL Classification: C39, C62, D51Identification, indeterminacy

On the Indeterminacy of New-Keynesian Economics

We study identification in a class of three-equation monetary models. We argue that these models are typically not identified. For any given exactly identified model, we provide an algorithm that generates a class of equivalent models that have the same reduced form. We use our algorithm to provide four examples of the consequences of lack of identification. In our first two examples we show that it is not possible to tell whether the policy rule or the Phillips curve is forward or backward looking. In example 3 we establish an equivalence between a class of models proposed by Benhabib and Farmer and the standard new-Keynesian model. This result is disturbing since equilibria in the Benhabib-Farmer model are typically indeterminate for a class of policy rules that generate determinate outcomes in the new-Keynesian model. In example 4, we show that there is an equivalence between determinate and indeterminate models even if one knows the structural equations of the modelIndeterminacy, identification

On the indeterminacy of new-Keynesian economics

We study identiÞcation in a class of three-equation monetary models. We argue that these models are typically not identiÞed. For any given exactly identiÞed model, we provide an algorithm that generates a class of equivalent models that have the same reduced form. We use our algorithm to provide four examples of the consequences of lack of identiÞcation. In our Þrst two examples we show that it is not possible to tell whether the policy rule or the Phillips curve is forward or backward looking. In example 3 we establish an equivalence between a class of models proposed by Benhabib and Farmer [1] and the standard new-Keynesian model. This result is disturbing since equilibria in the Benhabib-Farmer model are typically indeterminate for a class of policy rules that generate determinate outcomes in the new-Keynesian model. In example 4, we show that there is an equivalence between determinate and indeterminate models even if one knows the structural equations of the model. JEL Classification: C39, C62, D51, E52, E58IdentiÞcation, indeterminacy, new-Keynesian model, transparency

Shooting the Auctioneer

Most dynamic stochastic general equilibrium models of the macroeconomy assume that labor is traded in a spot market. Two exceptions by David Andolfatto and Monika Merz combine a two-sided search model with a one-sector real business cycle model. These hybrid models are successful, in some dimensions, but they cannot account for observed volatility in unemployment and vacancies. Following suggestions by Robert Hall and Robert Shimer, this paper shows that a relatively standard DSGE model with sticky wages can account for these facts. Using a second-order approximation to the policy function we simulate moments of an artificial economy with and without sticky wages and we document the dependence of unemployment and vacancy volatility on two key parameters; the disutility of effort and the degree of wage stickiness. We compute the welfare costs of the sticky wage equilibrium and find them to be small.