Imitators and optimizers in Cournot oligopoly

We analyze a symmetric n-firm Cournot oligopoly with a heterogeneous population of optimizers and imitators. Imitators mimic the output decision of the most successful firms of the previous round à la Vega-Redondo, F., [1997. The evolution of Walrasian behavior. Econometrica 65, 375–384]. Optimizers play a myopic best response to the opponents’ previous output. Firms make mistakes and deviate from their decision rules with a small probability. Applying stochastic stability analysis, we find that the long run distribution converges to a recurrent set of states in which imitators are better off than are optimizers.     

投资者有限理性行为的认知、心理基础

行为金融目前已经成为金融研究和实践的前沿领域。本文通过对国内外投资者有限理性行为的相关研究进行梳理,对投资者认知偏差和心理偏差进行分析,得到一个结论：只有准确把握有限理性投资者的各种认知、心理偏差,才能更深入理解市场异象和行为金融模型、优化投资决策。     

The power of imperfect imitation

We examine the power and limitations of imitation. Naive intuition may hold that the efficacy of imitation would be diminished by imperfections in copying high‐performing firms. Employing a computational model, we study the dynamics of imitation when firms are subject to bounded rationality that limits their ability to copy the market leader. We find that imperfect imitation can generate unexpectedly good outcomes for follower firms—indeed, better than the outcomes achieved if they were perfect imitators. Moreover, imperfect imitation, from time to time, enables follower firms to surpass superior firms. These findings suggest there is an adaptive role to mechanisms, such as bounded rationality, that make perfect imitation difficult. Copyright © 2012 John Wiley & Sons, Ltd.     

Heterogeneous expectations and long-range correlation of the volatility of asset returns

Inspired by the recent literature on aggregation theory, we attempt to relate the long-range correlation of the stock return volatility to the heterogeneity of the investors' expectations concerning the level of the future volatility. Based on a semi-parametric model of investors' anticipations, we make the connection between the distributional properties of the heterogeneity parameters and the auto-covariance/auto-correlation functions of the realized volatility. We report different behaviors, or change of convention, the observation of which depends on the market phase under consideration. In particular, we report and justify the fact that the volatility exhibits significantly longer memory during phases of a speculative bubble than during the recovery phase following the collapse of a speculative bubble.     

The role of birth order in child labour and schooling

Does when a child was born relative to his or her siblings affect whether the child attends school or participates in child labour? We investigate this question by estimating the causal effect of birth order on the probabilities of school attendance and child labour participation. To address the potential endogeneity of family size, we use instrumental variable approach where the proportion of boys in the family is used to instrument family size. Using a longitudinal household survey data from Ethiopia, we estimate unobserved effects bivariate probit instrumental variable model of school attendance and child labour choices. The results suggest that the probability of child labour participation decreases with birth order, but we find no evidence that suggests birth order affects the probability of school attendance. However, among children who are going to school, hours spent studying increases with birth order. Results from complementary time-use analysis reveal that there is no birth order effect on hours spent on household chore. However, hours spent on school increases with birth order, where the increase in hours spent on school seems to come from a decrease in hours spent on market work.     

上市公司高管失职行为的进化博弈分析

通过对上市公司高管失职和监事会监管的分析,引入有限理性的博弈概念,构建两者之间的进化博弈模型,分析上市公司高管行为监管的最优化问题。研究结果表明,上市公司高管和监事会之间不存在博弈的长期演化稳定策略,监事会对高管行为的监管存在"激励的悖论"。必须通过调整高管失职罚金及监事会监管成本、加强信息公开和完善法律法规等手段,解决高管失职行为的监管问题。     

中国股市波动有限理性归因实证分析

基于中国股市波动特征构建了中国股市的两类机构投资者（积极投资策略和保守型投资策略的机构投资者）投资理性模型。随后,借助计量软件对上证指数的时序数据和这一模型生成的数据进行拟合分析．分析这两个有限理性投资者对上证指数的超额波动所起的作用。最后,利用格兰杰检验法．检验这些变量之间的解释程度。     

华南理工大学南校区公共教学主楼建筑设计

结合华南理工大学新校区公共教学主楼的设计实践,文章对如何结合工科院校性格,设计简约理性、与环境和谐的教学建筑,提出了一些设计思路。     

Openness,Regional Trade Agreements and Growth: Evidence from Asia*

This paper assesses the relationship between regional trade agreements, trade integration and economic growth in 21 South and South‐East Asian countries over the period from 1980 to 2004. We aim to answer the following questions. First, how does the trade policy of a given country (and countries within the same region) affect a nation's domestic growth? Second, should developing economies in South and South‐East Asia engage in regional trade agreements (RTA) or move towards broad liberalization? Our results show that openness of either a single country or of its neighbors does not affect a nation's growth and that the impacts of RTA are unclear (if not detrimental to growth in some cases, once endogeneity is accounted for). Panel Granger‐causality tests running from openness to growth yield mixed results and some conclusions depend on the particular subsample under scrutiny.     

Do Private Tutoring Expenditures Raise Academic Performance? Evidence from Middle School Students in South Korea

To shed light on the effectiveness of educational inputs for student outcomes, this paper examines the effect of private tutoring expenditures on the academic performance of middle school students in South Korea. To address endogeneity, the paper uses instrumental variables, first‐difference, propensity‐score matching and nonparametric bounding methods. We apply these methods to a panel dataset from South Korea, the Korea Education Longitudinal Study. The results show that the true effect of private tutoring remains, at most, modest. Instrumental variables (first‐difference) estimates suggest that a 10‐percent increase in expenditure raises a test score by 0.03 standard deviations or 1.1 percent (0.002 standard deviations or 0.08 percent). Matching estimates imply that the same amount of increase in expenditure leads to a 0.33 to 0.72 percent higher average test score. The tightest bounds of the effect of tutoring reveal that a 10‐percent increase in expenditure improves the test score by a low of 0 to a high of 2.01 percent, while statistical tests fail to rule out zero effects. The modest effects of private tutoring found in the present study are comparable to the effects of public school expenditures on test scores and earnings estimated in previous studies.