Are Rational Expectations Equilibria with Private Information Eductively Stable?

The paper derives conditions for eductive stability of rational expectations equilibria in simple linear economic models with private information. Following Guesnerie (1992; 2002), the concept of eductive stability is used. It is shown that even in a private information setting, rational expectations equilibria might be justified as a result of mental process of reasoning of the agents. The paper considers an equilibrium concept, where the agents are unable to condition their forecasts on the actual market price. It is shown that eductive stability in this case requires that a condition is satisfied that is also relevant in the symmetric information case. This condition is compared to the respective stability condition that must hold if agents are able to use the current market price as an additional source of information. It turns out that the conditions for eductive stability that emerge under both equilibrium concepts differ.revised version received September 11, 2003     

Learning to believe in nonrational expectations that support pareto-superior outcomes

I consider the prototype New Keynesian macroeconomic model with subjective demand expectations of firms. In this model the firms' objective demand is log-linear in their relative price. Firms believe that their demand curve is linear or log-linear in their absolute price. They estimate the parameters of this curve by least squares from past observations on prices and quantities. The wage rate either clears the labor market given firms' demand perceptions or is given in the short run and changes according to a linear Phillips curve. In either setup of the model the interplay between learning and price setting confirms the subjective model. Among the long-run equilibria are solutions at which the representative household attains a higher level of utility as compared to the rational-expectations outcome. If the supply of labor depends upon the real wage, money is not neutral.     

Expectations and learning under alternative monetary regimes: an experimental approach

Summary We design and analyze experimental versions of monetary overlapping generations economies under alternative policy regimes. Economies with a constant level of real deficit financed through seignorage, economies in which the level of deficit is adapted in order to follow a monetary policy with a target rate of inflation, and economies with preannounced changes in deficit levels are reported here. We also examine the behavior of an economy with no stationary competitive equilibrium. Our time series are compared to rational expectations equilibrium paths and to adaptive learning dynamics.Financial support for our work from the Graduate School of the University of Minnesota, the National Science Foundation (SES-8912552), Richard M. and Margaret Cyert Family Funds, and the Ministry of Education of Spain is gratefully acknowledged. We wish to thank Javier Diaz-Giménez, Jean Michael Grandmont, Robert Lucas, Albert Marcet, Charles Plott, Edward Prescott, Thomas Sargent, Neil Wallace and Michael Woodford for commenting on our work. We also thank Vijay Rajan for developing the software for the computerized experimental environment, and Jackie Cuccaro and Dhananjay Gode for their research assistance.     

Evaluating how predictable errors in expected income affect consumption

This article studies whether anomalies in consumption can be explained by a behavioural model in which agents make predictable errors in forecasting income. We use a micro-data set containing subjective expectations about future income. This article shows that the null hypothesis of rational expectations is rejected in favour of the behavioural model, since consumption responds to predictable forecast errors. On average, agents who we predict are too pessimistic increase consumption after the predictable positive income shock. On average, agents who are too optimistic reduce the consumption.     

Rationalizable expectations and sunspot equilibria in an overlapping-generations economy

There are two theories for the treatment of market uncertainty: rationalizable expectations and sunspot equilibria. This paper shows how the game-theoretic solution concept of rationalizable expectations can be applied to an overlapping-generations exchange economy. Some general properties of these equilibria are discussed. It is shown that rationalizable-expectations equilibria are the predictions yielded by considering sunspot equilibria in which probability beliefs may differ across individuals. This result allows for a new interpretation of sunspot equilibria and helps to understand their relevance.     

宏观经济政策是否有效——基于理性预期模型的分析

自《通论》发表以来,关于宏观经济政策是否有效的争论一直贯穿于整个宏观经济学界。因此,从理性预期模型出发,对于宏观经济政策是否有效进行了再分析,通过博弈论思想的引入探究了宏观经济政策能否达到理想效果。在对扩张性宏观经济政策实际效果进行分析时指出了为何会出现“滞涨”,为何近年中国经济能够实现高增长低通胀的问题。     

Delegation and commitment in durable goods monopolies

This paper studies a simultaneous-move infinite-horizon delegation game in which the principal of a durable goods monopoly entrusts pricing decisions to a manager who enjoys consuming her monetary rewards but dislikes production effort. The delegation contract allows for continual interference with managerial incentives: in each period the principal rewards the manager according to her performance. We show that when the cost of delegation is low relative to profits, the principal can attain the precommitment price plan in a perfect rational expectations equilibrium. The paper analyzes the robustness of this result under alternative specifications of timing and objectives. We also provide a numerical characterization of the equilibrium strategies for the case of linear-quadratic payoffs.     

How do advertised brands benefit from private labels? An application of rational expectations models

Private labels have traditionally been viewed as a threat to advertised brands. Contrary to traditional wisdom, this study uses a two-asset rational expectations model to show that advertised brands could benefit from private labels. While the manufacturer’s advertising creates product differentiation, the retailer’s synchronous pricing strategy further enhances the product differentiation and raises profits as well as the efficiency of price discounts for the advertised brand. In addition, the existence of private labels improves the advertising efficiency, especially for newly introduced brands. The economic role of private labels is not limited to taking a free ride on the manufacturer’s advertising efforts, and this role cannot be replaced by another advertised brand.     

Money demand, the Cagan model, testing rational expectations vs adaptive expectations: The case of Turkey

This paper estimates the Cagan type demand for money function for Turkish economy during the period 1986:1–1995:3 and tests whether Cagan's specification fits the Turkish data using an econometric technique assuming that forecasting errors are stationary. This paper also tests the hypothesis that monetary policy was implemented in aiming to maximize the inflation tax revenue. Finally, the Cagan model is estimated with the additional assumption of rational expectations for Turkey for the considered period. First version received: March 1998/final version received: October 1998     

The random walk versus unbiased efficiency: can we separate the wheat from the chaff?

Abstract:

In the issue under investigation the wheat cannot be separated from the chaff because all we have is chaff. The random walk and unbiased efficiency are equally bad forecasters that should not be used as benchmarks for measuring forecasting accuracy. The simulation and econometric results show that when two forecasters are not independent they produce forecasts of similar quality, in which case it is erroneous to use the forward rate as a forecaster and the spot rate as a benchmark. Theoretical and intuitive explanations are presented for why the random walk and unbiased efficiency produce poor-quality forecasts that are almost identical. The failure of unbiased efficiency is explained primarily in terms of the post Keynesian view of the forward exchange rate.     

How does the diversity of investors’ beliefs affect stock price informativeness?

A growing number of studies have investigated the role of stock prices in aggregating private information and guiding resource reallocation. However, this article may be the first attempt to study how the diversity of beliefs affects stock price informativeness. The framework of the noisy rational expectations model shows that stock informativeness is determined by both the precision and use of private information in trading. If private beliefs about the value are highly diverse, the aggregate average opinion revealed in a stock’s price will be more accurate and, thus, more informative. As the price becomes more informative, however, individual investors will rely less on their private information. When this occurs, less private information will be absorbed in price, which, in turn, reduces price informativeness. Our model shows that the relationship between belief diversity and price informativeness is U-shaped in equilibrium.     

理性预期学派货币中性理论在中国的实证检验

利用中国1994年以来的经济数据,通过建立ARIMA模型和二阶段OLS模型对理性预期学派货币中性理论进行了检验。实证结果显示,短期内中国预期的货币供给冲击与非预期的货币供给冲击对产出都有显著影响,且非预期的货币供给冲击对产出影响更明显;但从长期看,预期货币与非预期货币对产出的正负效应相互抵消,中国货币政策表现为长期渐近中性。