Christophre Georges - Department of Economics - Hamilton College

Research Papers


Bounded Memory, Overparameterized Forecast Rules, and Instability

Economics Letters, 98:2, 2008, 129-135.

We consider an environment in which traders with finite memory update their forecast rules at random intervals by OLS. In this context, overparameterization of the forecast rules can destabilize the learning dynamics. This instability tends to be attenuated by greater memory and less frequent updating.


Staggered Updating in an Artificial Financial Market

Journal of Economic Dynamics and Control, 32:9, 2008, 2809-2825.

We consider an environment in which traders search for trading opportunities and update their forecast rules at random intervals. The staggering of this updating process across traders allows differences in opinion to persist over time, generating non-trivial price dynamics.


Learning Dynamics and Nonlinear Misspecification
In an Artificial Financial Market (with John C. Wallace)

Manuscript, Hamilton College, September 2003. Revised June 2008.

This paper considers the behavior of artificial agents who evolve their forecast rules over time in a simple financial market environment with over-the-counter trading. Asset price dynamics are driven by a combination of nonlinearly misspecified forecast rules and learning how to forecast. We explore the degree to which agents’ forecasts are drawn toward a minimal state variable learning equilibrium as well as a weaker long run consistency condition.

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Learning With Misspecification in an Artificial Currency Market

Journal of Economic Behavior and Organization, 60:1, 2006, Pages 70-84.

Agents evolve their forecast rules over time via a modified genetic algorithm in a simple artificial currency market. These forecast rules can be nonlinearly misspecified. When the misspecification is suppressed, learning tends to be complete. When it is not suppressed, learning can generate persistent exchange rate dynamics.


Learning Dynamics With Nonlinear Misspecification

Manuscript, Hamilton College, July 2002. Revised, October 2002.

This paper considers the behavior of artificial agents who evolve their forecast rules over time in a simple market environment. The forecast rules can be nonlinearly misspecified and thus induce interesting dynamics in the single state variable. Learning fails to eliminate this misspecification under the social learning algorithm considered here.

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Adjustment Costs, Learning, and Indeterminacy

Journal of Economic Dynamics and Control 28:1 October 2003, Pages 101-116

I compare the adjustment cost and learning approaches to resolving indeterminacy of perfect foresight equilibrium in a continuous time model with local indeterminacy. Rapid learning tends to select different perfect foresight equilibria of the original model than does the inclusion of vanishing adjustment costs. This difference has implications for the dynamic response of the economy to unanticipated shocks.


An Efficiency Wage Model With Persistent Cycles

Economics Bulletin, 5:3, 2002, pp. 1--6.

This note develops an efficiency wage model which displays persistent cycles under perfect foresight. Limit cycles arise from the dependence of current labor supply on both recent labor market conditions and the expected rate of job creation.


The Credit Channel of Monetary Policy Transmission: Evidence from Stock Returns in the 1990s (With Elizabeth J. Warner)

Economic Inquiry, 39:1, January 2001.

This paper offers a novel test of the credit view of the monetary policy transmission mechanism using stock market returns. We identify Fed policy shocks using newspaper accounts and track daily stock prices immediately following the shocks. If the credit channel is important, then firms that are dependent on bank credit and internal funds should receive a relatively greater benefit (loss) from a Fed easing (tightening) than firms with access to non-bank credit at favorable terms. We identify ten policy shocks during the expansion of 1993-94 and the "credit crunch" period of the 1990-91 recession and find little evidence supportive of an operative credit channel.


Profit-Shares, Bargaining, and Unemployment

Economic Inquiry, 36:2, April 1998.

This paper considers the effect of profit sharing on unemployment in a simple model with an employment externality, overhead costs, and free entry. When wages are determined by Nash bargains and employment is set by firms, equilibrium unemployment is unambiguously reduced by mandated profit sharing but may be either mitigated or exacerbated by a bargained profit share.


Debt and Taxes in a Marxian Growth Model (with Thomas R. Michl)

Review of Radical Political Economics, 28:3, September 1996.

We analyze government debt in the context of a growth model that is Marxian in the sense that its dynamics depend on a capitalist class which accumulates wealth in the form of capital and government debt.


Adjustment Costs and Indeterminacy in Perfect Foresight Models

Journal of Economic Dynamics and Control; 19:1-2, Jan.-Feb. 1995, pages 39-50.

This paper suggests a method for resolving indeterminacy of equilibrium in perfect foresight models and applies it to several existing models. Quadratic adjustment costs are introduced into models with multiple equilibria, and the limiting behavior of the resulting solutions is studied as the adjustment costs go to zero. The method is shown to be useful in selecting among feasible equilibria in examples in which there is local indeterminacy.


Unemployment Persistence under Profit Sharing

Economics Letters; 45:3, July 1994, pages 329-34.

In a simple dynamic model with an employment externality generated by union bargaining, an increase in a mandated rate of profit sharing reduces not only the steady-state unemployment rate but also the persistence of unemployment out of steady state.


A Dynamic Macroeconomic Model of the Labor-Managed Economy

Journal of Comparative Economics; 18:1, February 1994, pages 46-63.

This paper presents a macroeconomic model of a labor-managed economy under decentralized employment setting. In the model, individual labor-managed firms maximize rents. As a result, the behavior of aggregate employment hinges on the relationship between the employment strategies of individual labor-managed firms and opportunities for reemployment in other labor-managed firms. The author shows that, within the framework developed here, the allocation of labor in a labor-managed economy is identical to that in a competitive capital-managed economy and may be Pareto superior to that in a comparable imperfectly competitive capital-managed economy in which there is decentralized bargaining. These results are based on the unity of decision making and residual claimancy in the labor-managed firm but are fundamentally macroeconomic in nature. (c) 1994 Academic Press, Inc.


Emphasizing Controversy in the Economics Curriculum (with Fred Moseley and Christopher Gunn)

Journal of Economic Education 22:3, Summer 1991.

"The Status and Prospects of the Economics Major" (Siegfried et al. 1991) is a welcome and timely reexamination of the undergraduate economics curriculum. We enthusiastically agree with a number of points in the article, such as the suggestion to examine the underlying social values implicit in different economic theories, the emphasis on empirical tests of theories, the importance of active learning, the emphasis on contextual inquiry, and the related proposal for a breadth requirement. However, we disagree with the report on one important and far-reaching point: it completely ignores the controversial nature of economics. We argue that the economics curriculum should emphasize the important controversies within economics and should challenge students to learn to critically evaluate the different sides of these ongoing debates.