Choosing the choice: Reflections on modelling decisions and behaviour in demographic agent-based models

This paper investigates the issues associated with choosing appropriate models of choice for demographic agent-based models. In particular, we discuss the importance of context, time preference, and dealing with uncertainty in decision modelling, as well as the heterogeneity between agents in their decision-making strategies. The paper concludes by advocating empirically driven, modular, and multi-model approaches to designing simulations of human decision-making, given the lack of an agreed strategy for dealing with any of these issues. Furthermore, we suggest that an iterative process of data collection and simulation experiments, with the latter informing future empirical data collection, should form the basis of such an endeavour. The discussion is illustrated with reference to selected demographic agent-based models, with a focus on migration.     

On the expected discounted penalty function for a risk model with dependence under a multi-layer dividend strategy

In this article, we consider a dependent risk model in the presence of a multi-laydividend strategy. We construct the dependence structure between the claim size and interclaim time by a Farlie–Gumbel–Morgenstern copula. A piecewise integro-differential equations for the expected discounted penalty function with boundary conditions are established. A renewal equation satisfied by the expected discounted penalty function is obtained via the translation operator. Then, we provide a recursive approach to derive the analytical solution of the expected discounted penalty function. Finally, a numerical example is presented to illustrate the solution procedure.     

非连续不确定时间股息和可修正执行价格的权证定价研究

本文通过引入股息期货合约这一概念,得出考虑了非连续不确定时间股息的欧式权证定价模型,并结合我国市场上通行的权证行权价格修正条款,研究出适合我国市场权证的、考虑非连续不确定时间股息和可修正执行价格的欧式权证定价模型。并以阿胶EJC1为例进行了实证研究,研究表明新的模型较经典的Black-Scholes模型能更优地对中国权证进行定价。研究还表明:权证的行权价格修正条款并不能完全消除股息发放对权证价值的影响,权证价值仍然因为股息发放而减少。     

Social Work,Economic Conversion,and Community Practice:

With the fall of the Berlin Wall, and a new administration in Washington, hope is renewed for a peace economy. This hope is evidenced in the growth of new economic conversion projects ranging from legislative initiatives to new grassroots organizations. This exploratory survey of 15 directors of conversion projects sought to discover the kinds of strategies used and the degree of social work participation. Although results indicate that only one-third of the organizations involved social workers, there is much common ground between conversion strategies, community practice, and social work.     

Siblings and Sexual Orientation

Abstract

Lesbians, gay men, and bisexuals (LGBs) often have heterosexual siblings. The authors have conducted several research projects comparing siblings of different sexual orientations, given that siblings usually have the same ethnicity, race, parental socioeconomic status, and religious background. This review article presents research on LGBs and heterosexuals, all recruited via siblings. In general, heterosexual siblings are more mainstream in terms of being in long-term relationships, having children, belonging to a formal religion, and having more contact with their family of origin. LGB siblings are more politically liberal, more highly educated, and have moved away from their families of origin. The article speculates about how siblings who grow up in the same families could be so demographically different in adulthood.     

Intriguing yet simple skewness: kurtosis relation in economic and demographic data distributions,pointing to preferential attachment processes

In this paper, we propose that relations between high-order moments of data distributions, for example, between the skewness (S) and kurtosis (K), allow to point to theoretical models with understandable structural parameters. The illustrative data concern two cases: (i) the distribution of income taxes and (ii) that of inhabitants, after aggregation over each city in each province of Italy in 2011. Moreover, from the rank-size relationship, for either S or K, in both cases, it is shown that one obtains the parameters of the underlying (hypothetical) modeling distribution: in the present cases, the 2-parameter Beta function, itself related to the Yule–Simon distribution function, whence suggesting a growth model based on the preferential attachment process.     

The contemporary U.S. women's movement: An empirical example of competition theory

We use competition and resource mobilization perspectives to explain the rise of the contemporary U.S. women's movement. Our competition framework proposes that economic and sociodemographic changes since World War II increased competition between women and men in the marketplace. This increased competition provided motivation for the women's movement. We find support for this framework with national quantitative time-series data.     

Inbreeding effects on competition inTribolium

When replicate cultures ofT. confusum andT. castaneum are husbanded together under identical treatment conditions, sometimesT. confusum eliminatesT. castaneum, and other times,T. castaneum wins (i.e., competitive indeterminacy occurs). While several plausible explanations were advanced, the results of Mertz et al. (1976) implicated demographic stochasticity and not classical genetic founder effect as the predominant factor influencing the identity of the winning species. They also observed, however, that the size of the founding population had an influence on the competitive strength ofT. castaneum. The present study shows that the decline in competitive strength that accompanied decreasing founder size inT. castaneum can be amply explained by simple inbreeding depression. The eggs of inbred adults showed an approximate 15% reduction in hatchability when compared to outbred adults. No evidence was found that the decrease in competitive strength was due either to prior history differences or reduced genetic heterogeneity of the founding adults.     

公司监督与现金股利代理理论实证研究

用第一大股东持股比例、外部大股东持股比例和董事会中独立董事比例作为公司监督效果的代理变量,本文提供了一个现金股利能够减小代理成本的新证据。在控制了股利变动率、未预期净资产收益率、公司财务杠杆、公司规模以及经营业绩等因数的影响后,本文发现,市场对增加现金股利公告的反应与第一大股东持股比例正相关,与公司监督质量负相关。本文的结果暗示,在公司监督无效时,分派现金股利是一个降低代理成本的必要替代选择。     

性别观念、家庭地位与农村女性外出务工

利用第三期中国妇女社会地位调查数据实证研究了性别观念对农村已婚女性外出务工的作用,并在此基础上考察女性家庭地位在促进这一作用上所扮演的角色。研究结果发现：具有现代性别意识观念的女性显著地提高了其外出务工的概率,这中间起作用的主要是女性性别角色认同观念;同时女性家庭地位的调节作用明显,女性家庭地位的提高进一步强化了性别观念对外出务工的影响效应。在解决内生性问题和进行稳健性检验后结果依然显著。对受教育程度和区域的差异性分析中发现,农村中低学历女性群体和中西部女性群体性别观念对其外出务工的作用存在显著的影响,而在高学历群体和东部地区并不显著。研究尝试为理解我国农村女性外出务工的现象提供一个解释视角,倡导通过性别平等来释放女性在家庭社会经济中的性别红利。