The Econometrics and Economics of the Employment Effects of Minimum Wages: Getting from Known Unknowns to Known Knowns

I discuss the econometrics and the economics of past research on the effects of minimum wages on employment in the United States. My intent is to try to identify key questions raised in the recent literature, and some from the earlier literature, which I think hold the most promise for understanding the conflicting evidence and arriving at a more definitive answer about the employment effects of minimum wages. My secondary goal is to discuss how we can narrow the range of uncertainty about the likely effects of the large minimum wage increases becoming more prevalent in the United States. I discuss some insights from both theory and past evidence that may be informative about the effects of high minimum wages, and try to emphasize what research can be done now and in the near future to provide useful evidence to policy‐makers on the results of the coming high minimum wage experiment, whether in the United States or in other countries.     

Cost monotonicity, consistency and minimum cost spanning tree games

We propose a new cost allocation rule for minimum cost spanning tree games. The new rule is a core selection and also satisfies cost monotonicity. We also give characterisation theorems for the new rule as well as the much-studied Bird allocation. We show that the principal difference between these two rules is in terms of their consistency properties.     

一种城市物流分区配送方法的研究

提出了基于区位理论的城市物流分区配送的数学模型和算法实现方法，实验证明。该方法具有计算效率高，求解精度适中的特点。     

How many voters are needed for paradoxes?

Summary. This paper presents a general procedure for finding profiles with the minimum number of voters required for many important paradoxes. Borda's and Condorcet's classic examples are revisited as well as generalizations. Using Saari's procedure line, we obtain an upper bound for the minimum number of voters needed for a profile for which the Condorcet winner is not strictly top ranked for all weighted positional procedures. Also we give a simple upper bound on the minimum number of voters needed for a set of prescribed voting outcomes. In contrast to situations wherein small numbers of voters are needed, we consider paradoxes requiring arbitrarily large numbers of voters as well as large numbers of alternatives. Finally we indicate connections with statistical rank based tests. Received: April 18, 2001; revised version: May 25, 2001     

关于期权薪酬会计计量方法的思考

股票期权薪酬计量方法的选用一直以来都存在争议,采用不同的计量方法会直接影响到股票期权会计信息的真实性和透明度。本文通过对分别运用内在价值法、最小价值法和公允价值法中的B-S模型和二叉树模型对期权薪酬价值的计算分析,来说明何种计量方法能最有效地实现期权薪酬核算的目的。     

Diversification Benefits of Japanese Real Estate Over the Last Four Decades

This paper studies the benefits of diversifying into real estate and other assets that typify the wealth held by Japanese investors. We examine movements in mean variance frontiers by employing spanning tests to assess the statistical significance of frontier shifts. We also investigate the impact of shifts in mean variance frontiers before and after the precipitous decline in Japanese real estate and stock market values that began in 1990. Spanning tests show that real estate, short and long-term bonds, and Japanese equity provide significant diversification benefits. We find that mean variance frontiers shift after 1990. Statistically significant shifts are also economically important as measured by Sharpe ratio changes. Although significant, the portfolio weights on Japanese real estate are relatively small compared to their composition found in surveys of Japanese household wealth.     

A semi-analytic method for valuing high-dimensional options on the maximum and minimum of multiple assets

Valuing high-dimensional options has many important applications in finance but when the true distributions are unknown or complex, numerical approximations must be used. Approximation methods based on Monte-Carlo simulation show a steep trade-off between estimation accuracy and computational efficiency. This article presents an alternative semi-analytic approximation method for pricing options on the maximum or minimum of multiple assets with unknown distributions. Computational efficiency is shown to improve significantly without sacrificing estimation accuracy. The method is illustrated with applications to options on underlying assets with mean-reverting prices, time-dependent correlations, and stochastic volatility The authors would like to thank the two anonymous referees, the associate editor, and Dr. Jess H. Chua at the University of Calgary for valuable comments and insights on this research. This research was partly supported by NUS grant R-146-000-059-112     

我国最低工资政策的就业效应——基于北京市和重庆市建筑业的分析

VAR模型对最低工资就业效应的分析结果显示:北京市的最低工资标准与建筑业就业只是在数理统计上存在关系,并没有实际的经济意义;最低工资对重庆市建筑业的微弱负影响可以忽略不计。最低工资的就业效应并不明显,可以紧密联系行业平均工资来调整最低工资标准,以保障劳动者的基本生活。     

城市低保制度在邵阳市区的实施情况调查——以对212户低保受助者的调查为例

为了解城市低保制度的实施情况,从中发现存在的问题以及解决这些问题的方法,相关研究机构组织了由大学生组成的调查员对邵阳市城区内多个社区两百余户低保受助者进行了走访调查。调查结果显示,低保制度能发挥居民最低生活保障的作用,是一项完成了基本任务的顶层设计;自谋生计是大部分低保受助者的主要经济来源,而低保制度不具备"养懒汉"的经济可能性。     

Certification and minimum quality standards when some consumers are uninformed

We compare certification to a minimum quality standard (MQS) policy in a duopolistic industry where firms incur quality-dependent fixed costs and only a fraction of consumers observe the quality of the offered goods. Compared to the unregulated outcome, both profits and social welfare would increase if firms could commit to producing a higher quality. An MQS restricts the firms׳ quality choice and leads to less differentiated goods. This fuels competition and may therefore deter entry. A certification policy, which awards firms with a certificate if the quality of their products exceeds some threshold, does not restrict the firms׳ quality choice. In contrast to an MQS, certification may lead to more differentiated goods and higher profits. We find that firms are willing to comply with an ambitious certification standard if the share of informed consumers is small. In that case, certification is more effective from a welfare perspective than a minimum quality standard because it is less detrimental to entry.