A Pearson's test for symmetry with an application to the Spanish business cycle

In this paper, we look for asymmetries in the Spanish business cycle. To that end, we firstly propose an easy nonparametric testing procedure to test for symmetry based on a Pearson's chi-squared statistic, which we call P-test. Then, we test for two popular forms of asymmetry, deepness and steepness, using a battery of nonparametric tests. In addition, we analyse possible complementarities between the tests used in this paper, and we compute p-value adjustments for multiple tests.     

The term structure of real interest rates: theory and evidence from UK index-linked bonds

This paper studies the behavior of the default-risk-free real term structure and term premia in two general equilibrium endowment economies with complete markets but without money. In the first economy there are no frictions as in Lucas (Econometrica 46 (1978) 1429) and in the second risk-sharing is limited by the risk of default as in Alvarez and Jermann (Econometrica 68 (2000) 775; Rev. Financial Studies 14 (2001) 1117). Both models are solved numerically, calibrated to UK aggregate and household data, and the predictions are compared to data on real interest rates constructed from the UK index-linked data. While both models produce time-varying risk or term premia, only the model with limited risk-sharing can generate enough variation in the term premia to account for the rejections of expectations hypothesis.     

Sunspot fluctuations in dynamics with predetermined variables

Summary. In this paper, I study the existence of Sunspot Equilibria in a general framework whose dynamics allow for the presence of predetermined variables in the system. The main motivation for this research comes from the fact that previous studies did not allow for such predetermined variables which, nevertheless, appear quite naturally in economic models. I show, for a non-negligible subset of dynamics with predetermined variables verifying usual assumptions, the existence of Stationary Sunspot Equilibria fluctuating between an arbitrary finite number of states arbitrarily close to a steady state. Received: March 1, 1995; revised version September 18, 1996     

价值型投资在中国证券市场上的有力证据

本文给出了1994年至2005年间价值型投资在中国A股市场中的有力证据。Fama—MacBeth回归表明在中国A股市场中存在着显著的市盈率和市净率溢价，1994年至2005年中牛市和熊市的滚动策略显示了我国A股市场中的价值效应，并且风险和收益之间基本上呈现出收益大、风险大的特征。本文的实证研究结果将有助于中小投资者以及机构投资者的长期投资决策。     

试论现阶段电子商务的交易安全技术

随着信息技术日新月异的发展，人类正在进入以网络为主的信息时代，基于Intemet开展的电子商务已逐渐成为人们进行商务活动的新模式。但电子商务的安全问题变得越来越突出，建立一个安全、便捷的电子商务应用环境，关键在于保证整个商务活动中信息的安全性，使基于Intemet的电子交易方式与传统交易方式一样安全可靠。电子商务安全包括计算机网络安全和商务交易安全。商务交易安全主要是通过加密技术、安全机制、安全协议进行保证的。     

电子商务时代柠檬问题的出现及解决

电子商务时代质量的不确定性引起了柠檬问题的出现,而柠檬问题会导致产品和服务质量降低的不对称信息趋势,所以解决这个问题的方法就是要把相关信息告知消费者,让消费者对产品的质量有把握。本文针对电子商务时代的柠檬问题给出了四个解决方案,并重点讨论了利用中介的解决方案,分析了中介在电子商务中的重要作用和中介改变电子商务市场效率的问题。     

我国合理市盈率与股市泡沫的实证分析

市盈率是被广泛用来测量股市泡沫风险的一个重要指标。本根据“股票的理论价格应该是未来各期红利的贴现之和”这一传统金融理论，导出用以衡量股市泡沫成分的基准——合理市盈率的计算方法。通过分析发现市盈率的合理值是一个动态值，据此测量出的上海A股市场泡沫成分自1993年以来呈明显下降趋势，说明我国股票市场上的投资日趋成熟，投资行为日趋理性。     

Investment-specific shocks and external balances in a small open economy model

Abstract.  We set up a standard small open economy business cycle model driven by government spending shocks, neutral productivity (TFP) shocks, and investment-specific shocks. The model is calibrated to quarterly Canadian data and its predicted moments and sample paths are compared with their Canadian counterparts. We find that the model captures the dynamics in investment and in the trade balance better than special cases of the model where either one of the productivity shocks is omitted. More specifically, the model matches the variance of the trade balance-output ratio, its correlation with output and its autocorrelation. It also matches the output-investment correlation.     

Convergence in West German Regional Unemployment Rates

Abstract. Differences in regional unemployment rates are often used to describe regional economic inequality. This paper asks whether changes in regional unemployment differences in West Germany are persistent over time. Understanding the persistency of regional unemployment differences helps us to assess how effective regional policy can be. While univariate tests suggest that changes in regional unemployment differences are persistent in West Germany, more powerful panel tests lend some support to the hypothesis that regional unemployment rates converge. However, these tests reveal a moderate speed of convergence at best. Because there is a structural break following the second oil crisis, we also use tests that allow for such a break. This provides evidence for both convergence and quick adjustment to an equilibrium distribution of regional unemployment rates that is, however, subject to a structural break.     

Buyer power and supplier incentives

This paper analyzes the origins and welfare consequences of buyer power. We show that if suppliers are capacity constrained or have strictly convex costs, there are two different channels through which large buyers can obtain more favorable terms from their suppliers. In particular, we show how the presence of large buyers can then erode the value of suppliers’ outside option. Somewhat surprisingly, we show how this can induce suppliers to undertake strategies that lead to higher output and potentially higher welfare.