10,608 research outputs found
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
Crystallization of random trigonometric polynomials
We give a precise measure of the rate at which repeated differentiation of a
random trigonometric polynomial causes the roots of the function to approach
equal spacing. This can be viewed as a toy model of crystallization in one
dimension. In particular we determine the asymptotics of the distribution of
the roots around the crystalline configuration and find that the distribution
is not Gaussian.Comment: 10 pages, 3 figure
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.
Hubble space telescope: Pointing error effects on nonlinear ball joints
The Hubble Space Telescope pointing error produced by optical benches mounted on free ball joints is examined. Spacecraft cable connections are assumed to produce translational and rotational damping and restoring forces which act through the optical bench center of mass. The nonlinear dynamics are modeled and then implemented using an existing computer program for simulating the vehicle dynamics and pointing control system algorithm. Results are presented for the test case which indicate acceptable performance
A method to generate structural impulse-responses for measuring the effects of shocks in structural macro models
We develop a technique for analyzing the response dynamics of economic variables to structural shocks in linear rational expectations models. Our work differs fromstandard SVARs since we allow expectations of future variables to enter structural equations. We show how to estimate the variance-covariance matrix of fundamental and non-fundamental shocks and we construct point estimates and confidence bounds for impulse response functions. Our technique can handle both determinate and indeterminate equilibria. We provide an application to U.S. monetary policy under pre and post Volcker monetary policy rules. JEL Classification: C39, C62, D51, E52, E58Identification, indeterminacy, rational expectations models
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