The Extended Generalized Gamma Model and its Special Cases: Applications to Modeling Marriage Durations

The paper demonstrates how various parametric models for duration data such as the exponential, Weibull, and log-normal may be embedded in a single framework, and how such competing models may be assessed relative to a more comprehensive one. To illustrate the issues addressed, the survival patterns of marriages among 1203 Swedish men born 1936–1964 are studied by parametric and non-parametric survival methods. In particular, we study the sensitivity of model-choice with respect to level of aggregation of the time variable; and of covariate-effects with respect to the model chosen. In accordance with previous works our empirical results indicate that the choice of a parametric model for the duration variable is affected by the level of time aggregation. In contrast to previous results, however, our analysis shows that estimates of covariate effects are not always robust to distributional assumptions for the duration variable.     

Why Punish? Social reciprocity and the enforcement of prosocial norms

Recently economists have become interested in why people who face social dilemmas in the experimental lab use the seemingly incredible threat of punishment to deter free riding. Three theories with evolutionary microfoundations have been developed to explain punishment. We survey these theories and use behavioral data from surveys and experiments to show that the theory called social reciprocity in which people punish norm violators indiscriminately explains punishment best.JEL Classification: C91, C92, D64, H41 Correspondence to: Jeffrey P. CarpenterWe thank Carolyn Craven, Corinna Noelke and two referees for comments, and Middlebury College for financial assistance. In addition, Carpenter acknowledges the support of the National Science Foundation (SES-CAREER 0092953).     

Toward a Phylogenetic Reconstruction of Organizational Life

Synopsis Classification is an important activity that facilitates theory development in many academic disciplines. Scholars in fields such as organizational science, management science and economics and have long recognized that classification offers an approach for ordering and understanding the diversity of organizational taxa (groups of one or more similar organizational entities). However, even the most prominent organizational classifications have limited utility, as they tend to be shaped by a specific research bias, inadequate units of analysis and a standard neoclassical economic view that does not naturally accommodate the disequilibrium dynamics of modern competition. The result is a relatively large number of individual and unconnected organizational classifications, which tend to ignore the processes of change responsible for organizational diversity. Collectively they fail to provide any sort of universal system for ordering, compiling and presenting knowledge on organizational diversity. This paper has two purposes. First, it reviews the general status of the major theoretical approaches to biological and organizational classification and compares the methods and resulting classifications derived from each approach. Definitions of key terms and a discussion on the three principal schools of biological classification (evolutionary systematics, phenetics and cladistics) are included in this review. Second, this paper aims to encourage critical thinking and debate about the use of the cladistic classification approach for inferring and representing the historical relationships underpinning organizational diversity. This involves examining the feasibility of applying the logic of common ancestry to populations of organizations. Consequently, this paper is exploratory and preparatory in style, with illustrations and assertions concerning the study and classification of organizational diversity.     

The Effect of Respondent Experience/Knowledge in the Elicitation of Contingent Values: An Investigation of Convergent Validity,Procedural Invariance and Reliability

Tests of convergent validity and procedural invariance were used to investigate whether individuals lacking direct experience with a commodity can provide valid responses to contingent-valuation questions eliciting ex post use values. Convergent validity between samples with and without experience was shown to hold for dichotomous-choice responses, but not for open-ended responses.     

Strategic Firm Behavior Under Average-Revenue-Lagged Regulation

Price caps have been shown to have incentive properties superior to traditional rate of return regulation. Average-revenue-lagged regulation (ARL) is attractive in that steady-state prices are known to be efficient. We show that the ARL scheme can be manipulated by the firm so as to yield the unregulated global profit maximum. While tests exist that can provide the regulator with evidence of this strategic behavior, we also demonstrate that the unregulated global profit maximum will not be attainable if Laspeyres (L) regulation is employed.Jel classification: L43, L51I would like to thank Michael Crew and an anonymous referee for their extremely helpful suggestions.     

基于CAPM的中国股市羊群行为研究——兼与宋军、吴冲锋先生商榷

本文首先对宋军和吴冲锋的《基于股价分散度的金融市场羊群行为研究》一文进行了分析 ,指出其在分析方法和论证逻辑两方面存在的问题。随后 ,本文以资本资产定价模型 (CAPM)为基础 ,建立了一个更为灵敏的羊群行为检验模型 ,并据此对我国股市进行了实证检验。研究结果表明 :在政策干预频繁和信息不对称严重的市场环境下 ,我国股市存在一定程度的羊群行为 ,并导致系统风险在总风险中占有较大比例     

选课制下排课模式的研究

选课制的实施有利于增强学生学习过程的自主性。而与选课制相适应的排课模式有其自身的特点 ,需要在实践过程中不断地探索、研究与创新     

Politically stable pay-as-you-go pension systems: When the social-insurance budget is too small in a democracy

The essay analyzes in an overlapping-generations model, to which extent a pay-as-you-go pension system will be the outcome of majority voting, given specific institutional set-ups. Clearly, the vote of an active person depends on his expectations about how the present decision (i.e., his contribution) is linked to the future (i.e., his benefits), when he will be retired. In the paper we employ the assumption of a basic social contract where each active voter's future benefits are positively related to his contributions. It is shown that in this framework a steady-state with a positive (though lower than optimal) level of the pension system exists, even if a new majority decision about the system takes place every period.     

税务征收体制下的基本养老保险个人缴费基数:问题、机制与对策

个人缴费基数是基本养老保险制度的关键参量之一。我国现行的个人缴费基数政策主要问题在于:一是核定过程复杂且难度大,因核定不到位导致的少缴和漏缴现象突出;二是以上年度月平均工资作为当期缴费基数的规定不合理;三是以职工平均工资的60%作为缴费基数下限加重了低工资收入者的缴费负担,易对其形成制度性挤出;四是社会保险费的征管流程存在制度性漏洞。在统筹推进基本养老保险全国统筹和社会保险费征收体制改革的关键时期,完善个人缴费基数政策应以增强规范性和统一性为重点。基于个人缴费基数的"两阶段"形成机制,本文建议应考虑工资结构差异,对企业职工、机关事业单位职工和灵活就业人员分别使用排除法、列举法和定额法来核定应缴费工资;将缴费基数下限降低至各地最低工资标准;将计算周期改为与工资、薪金所得个人所得税保持一致,实现税费同步计算、同征同管。