对西方主流宏观经济学均衡假定的反思——从凯恩斯主义的投资恒等于储蓄说起

自从凯恩斯的《通论》出版以来,宏观经济学就逐渐成为一个比较系统而相对独立的学科,后人将凯恩斯的短期经济增长模型进一步长期化为外生和内生经济增长理论.纵观主流宏观经济学的理论构建,几乎都有一个共同的假设:市场能够自动实现均衡,但是,正是这个假设将西方主流宏观经济学引入了歧途.对于原凯恩斯主义、新古典综合派、新凯恩斯主义、哈罗德-多马的古典经济增长理论和索洛的新古典增长理论、新古典宏观经济学派而言,它都是一个难以回避的硬伤.     

Microfoundations

This paper argues that the microfoundations programme can be understood as an implementation of an underlying methodological principle—methodological individualism—and that it therefore shares a fundamental ambiguity with that principle, viz, whether the macro must be derived from and therefore reducible to, or rather consistent with, micro-level behaviours. The pluralist conclusion of the paper is not that research guided by the principle of microfoundations is necessarily wrong, but that the exclusion of approaches not guided by that principle is indeed necessarily wrong. The argument is made via an examination of the advantages claimed for dynamic stochastic general equilibrium models, the relationship between parts and wholes in social science, and the concepts of reduction, substrate neutrality, the intentional stance and hypostatisation.     

The Lack of International Consumption Risk Sharing: Can Inflation Differentials and Trading Costs Help Explain the Puzzle?

The bulk of evidence on the lack of international risk sharing is based on regressions of idiosyncratic consumption growth on idiosyncratic output growth. This paper argues that the results from such regressions obtained from international data are, however, not directly comparable to those based on regional data: the standard practice of running such regressions on international data fails to account for persistent international differentials in consumer prices, whereas—implicitly—most of the literature based on regional data has accounted for these differences. When risk sharing regressions are set up in conceptually the same way in international and regional data sets, the estimated coefficients are also very similar. To explore this result further, we adapt the variance decomposition of Asdrubali et al. (Q J Econ 111:1081–1110, 1996) to allow for deviations from purchasing power parity across countries. While quantity (income and credit) flows are the dominant channel of risk sharing among regions, relative consumption and output price (internal terms of trade) fluctuations account for the bulk of the deviation from the complete markets outcome in international data. To the extent that persistent differences in consumer prices are an indication of goods market segmentation, our findings provide empirical evidence for the proposition by Obstfeld and Rogoff (NBER Macroeconomics Annual 2000, 2000) that segmented international goods markets rather than asset market incompleteness may account for the (apparent) lack of risk sharing between countries.

Chaotic Exchange Rate Dynamics Redux

This article generalizes the results shown in De Grauwe, Dewachter, and Embrechts (1993) in a more sophisticated framework. In their model, the speculative dynamics resulting from the interaction between chartists and fundamentalists are incorporated into a Dornbusch-style model to generate a chaotic nominal exchange rate. Here the model of Obstfeld and Rogoff (1995, 1996) replaces the Dornbusch model, and chaotic solutions are still shown to be possible for sensible parameter values.     

Enhancing the teaching of introductory economics with a team-based,multi-section competition

The authors describe a unique approach to enhancing student learning at the introductory economics level that utilizes a multi-section, team-based competition. The competition is structured to supplement learning throughout the entire introductory course. Student teams are presented with current economic issues, trends, or events, and use economic tools and theories to comprehensively examine the topics. Students present their analyses in their own sections with one team from each section moving on to compete in an inter-section round. Students are judged on technicality, creativity, and applicability of economic concepts. The competition has the potential to advance students' creativity, collaboration, communication, and critical and analytical thinking skills, while enhancing their ability to apply foundational economic concepts to real-world settings.     

Financial Exposure and the International Transmission of Financial Shocks

This paper analyzes the transmission mechanism of banking sector shocks in an international real business cycle model with heterogeneous bank sizes. We examine to what extent the financial exposure of the banking sector affects the transmission of foreign banking sector shocks. In our model, the more exposed domestic banks are to the foreign economy via lending to foreign firms, the greater are the spillovers from foreign financial shocks to the home economy. The model highlights the role of openness to trade and the dynamics of the terms of trade in the international transmission mechanism of banking sector shocks: spillovers from foreign banking sector shocks are greater the more open the home economy is to trade and the less the terms of trade respond to foreign shocks.     

Undergraduate Economics Education in English and Welsh Universities

A professor experienced in both the United Kingdom's and the United States' educational systems, the author describes and compares the two countries' economic education objectives and practices.     

Optimal exchange-rate policy in a low interest rate environment

This paper examines optimal monetary policy with an explicit zero lower bound in a small open-economy model. The paper finds that the gains from commitment are increasing in the openness of the economy while the optimal rate of inflation is decreasing in the openness of the economy. These results imply that the main findings of Adam and Billi (2007) for a closed-economy model are also true for an open-economy model. Finally, the paper finds that the effectiveness of the exchange-rate channel as a stabilization tool in the low interest rate environment depends on whether the central bank can make a credible commitment. If the central bank cannot commit and makes monetary-policy decisions on a discretionary basis, the optimal path of the nominal exchange rate will exhibit an appreciation, rather than depreciation as suggested in the literature.     

International monetary policy coordination in a new Keynesian model with NICE features

The authors provide a static two-country new Keynesian model to teach two related questions in international macroeconomics: the international transmission of unilateral monetary policy decisions and the gains coming from the coordination monetary rules. They concentrate on “normal times” and use a thoroughly graphical approach to analyze the questions at hand. In this setting monetary policy is conducted using interest rates rules and economic integration between nations does not necessarily create the case for the coordination of monetary policy. In particular, they show that the conduct of optimal national monetary policies does not make any difference with the coordination of national policies, as this creates a situation where the international monetary system operates “Near an International Cooperative Equilibrium” (NICE).