Some extensions of the keyfitz momentum relationship

A stable population, such that the total birthrateB(t) =B _o e ^ro^t, is abruptly altered by modifying the age-specific birth rate,m(x). The survivor function remains unaltered. The modified population ultimately settles down to a stable behavior, such thatB(t) =B ₁ e ^r ₁ ^t . It is shown thatB ₁/B ₀ = (R ₀ ?R ₁)/[(r ₀ ?r ₁)R ₀ Z ₁], whereR ₀,R ₁ are the net reproduction rates before and after the change, and \(\bar Z_1 \) expected age giving birth for the stable population after the change. The age structure and transients resulting from the change are also described. The effect of an abrupt change in the survivor functionl(x) is also investigated for the simple case where the change is caused by alteringl(x) toe ^?λx l(x). It is shown that the above ratio becomes \(B_1 /B_0 = N_1 /N_0 = [1 - \smallint _0^\infty e^{ - kx} g(x)dx]/\bar Z_1 \lambda \) , whereN refers to the numbers in the population,k =r ₀ + λ, andg(x) =m(x)l(x), the value before the change. A measure for the reproductive worth of the population is also established.     

Gender and racial inequities in retirement resources

Two waves of a Social Security Beneficiary survey were analyzed to consider differences in the retirement resources of women and men based on marital status and race/ethnicity. Despite increased workforce participation the economic situation of single women, including white women, worsened over time. A bifurcation in retirement resources was found, with men relying more on private income sources and women depending more on Social Security. Current retirement policies based on privatization will continue to adversely impact women who work at low-paying jobs, receive lower wages, and live longer than men.     

美国核能工业管制体系的演变及其借鉴分析

在原子时代的开端 ,核能的前途似乎是一片光明。在五六十年代的美国 ,核能经历了一个不受约束的扩张阶段。但是 ,随后公众的支持和经济利益转向了反对核能技术。从 70年代后期开始 ,美国公用事业公司再没有订购新的核电站。美国核能管制体系在决定核能命运的选择过程中扮演了一个没有预计到的重要角色。文章详细地描述了这个体系的演变历程 ,以及它在公众对核能的信心的消逝这个过程中所产生的影响 ,核能管制体系对公众的这种信心的影响主要有三个方面 :管制体系具有的促进和管制核能这两个目标之间的冲突、管制过程的保密以及一种幼稚的与大众沟通的策略     

Perceived Environmental Uncertainty, Entry Mode Choice and Satisfaction with EC-MNC Performance

Previous theoretical and empirical research provides substantial support for a contingency approach toward international entry-mode selection. Similarly, additional empirical research supports the notion that different international ownership-based entry modes tend to be associated with varying performance levels. In this study we provide an initial attempt to use Werner, Brouthers and Brouthers' (1996) multiple measures of Perceived Environmental Uncertainty (PEU) to determine the entry mode choices of firms and link these risk-adjusted mode choices to managerial satisfaction with firm performance. We hypothesize and find that firms which make PEU risk-adjusted entry mode choices are significantly more satisfied with their firm's performance than firms whose entry mode choices cannot be predicted using multiple PEU risk measures.     

A Bayesian approach to Weibull survival models—Application to a cancer clinical trial

In this paper we outline a class of fully parametric proportional hazards models, in which the baseline hazard is assumed to be a power transform of the time scale, corresponding to assuming that survival times follow a Weibull distribution. Such a class of models allows for the possibility of time varying hazard rates, but assumes a constant hazard ratio. We outline how Bayesian inference proceeds for such a class of models using asymptotic approximations which require only the ability to maximize the joint log posterior density. We apply these models to a clinical trial to assess the efficacy of neutron therapy compared to conventional treatment for patients with tumors of the pelvic region. In this trial there was prior information about the log hazard ratio both in terms of elicited clinical beliefs and the results of previous studies. Finally, we consider a number of extensions to this class of models, in particular the use of alternative baseline functions, and the extension to multi-state data.     

Direct and indirect effects of unionization on the wage levels of nurses: A case study of New Jersey hospitals

This study examines the determination of wage rates for nurses in hospital employment. Of particular concern is the effect of the recent increase in unionization by nurses on their wages, both directly and indirectly via threats from competing hospitals’ unionization. To improve on earlier work, the data are disaggregated and gathered from only one state to standardize for the legal, licensing, and reimbursement systems. We also look at the difference between highly skilled professional nurses, RN’s, and more general and less professional nurses, LPN’s. The results show that working conditions and competition in the market influence the wage rate as one would expect. The unionization of nurses, however, affects the wage levels differently for the two groups. We would like to thank Professors Robert Higgs and Alan Childs of Lafayette College, Professor David Fairris of Williams College, Professor James C. Luzier of Muhlenberg College, and an anonymous referee for their helpful comments and suggestions.     

The changing determinants of U.S. Unionism: An analysis using worker-level data

In contrast to much of the literature examining the decline of trade unions in the United States, I examine the decline from the perspective of the individual employee. Worker-level data combined with industry-level data for the years 1972 and 1987 are used to investigate the decline. The central findings are that the changing sex and race composition of the labor force and increases in management resistance have had little influence, while gains in educational levels, changing occupations, and reductions in the economies of scale of union organizing have contributed greatly to the decline.     

Garfinkel before ethnomethodology

A short story titled “‘Color Trouble’” by Harold Garfinkel was published inOpportunity in 1940,The Best Short Stories 1941, andPrimer for White Folks in 1945. Garfinkel wrote this short story before World War II while a research fellow at the University of North Carolina, Chapel Hill under Howard W. Odum, the founder ofSocial Forces “‘Color Trouble’” narrates poignantly the racial victimization of a young black woman traveling on a public bus through the State of Virginia. The short story provides sociologists with a different medium through which to examine the seminal interests of ethnomethodology’s founder. In a literary form, the short story depicts such ethnomethodological concepts as the breaching experiment, the “et cetera clause,” “ad hocing,” and the status degradation ceremony. Garfinkel’s “‘Color Trouble’” also suggests the way in which ethnomethodology overlaps with, as well as diverges from, Erving Goffman’s dramaturgical perspective. He received his doctoral degree from the graduate program in sociology at York University, Toronto, Ontario. His article “Autonomy and Responsibility in Social Theory” will appear inCurrent Perspectives in Social Theory, Volume 10.