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.     

Book Reviews

This article examines some difficulties associated with the Haynes–Stone model and attempts to clarify how the model can be justified as representing the hypothesis that “quantity is demand determined and price is supply determined.” It also argues that the applications of such a model as was done by Haynes and Stone might not have resolved the controversies related to the Phillips curve and the supply function of exports (or imports).     

Science,measurement, and validity: Is completion of Samuel Messick's synthesis possible?

Messick's (1989) theory of test validity is profoundly influential (Hubley and Zumbo, 1996; Angoff, 1988) in part because it brings together disparate contributions into a unified framework for building validity arguments. At the heart of Messick's theory lies a synthesis of realism and constructivism with respect to both scientific facts and measurement. Within this synthesis there remains a tension between the evidential basis and the consequential basis for test interpretation and use. This cannot be sidestepped simply by limiting the evidential basis to test interpretation and the consequential basis to test use: Interpretation and use are not so easily held separate. The roles of constructivism and context in Messick's theory underline the inherent link between facts and values, but the assumption that facts are objective and values are subjective goes unquestioned in Messick's theory. The inherent link between facts and values combines with this assumption to produce the unresolved tension in Messick's theory. This suggests that a unified theory of test validity requires a theory of value justification.     

“Can/Should/Does One Size Fit All? Does the Pacific Sociological Association Still Meet the Needs of Faculty Members at PhD-Granting Institutions?”

This article addresses the concern expressed by many within the Pacific Sociological Association in recent years that their regional organization is increasingly seen by Research I University sociologists as no longer meeting their professional needs, thus leading to (a) decreasing rates of membership and participation within, (b) a decline in the amount of high quality professional work associated with, and (c) a diminishment of the professional status of, the PSA. Using data gained from a membership survey of sociologists at the 29 Research I Universities in the Western Region of the United States and Canada, the empirical basis of these claims is examined, and their possible implications explored. The results of this investigation suggest that although PSA membership among faculty members at PhD-granting institutions may have declined somewhat over time, this has occurred for a number of very comprehendible reasons, some associated with but others external to the Pacific Sociological Association as a professional organization. In light of these findings, it is the main recommendation of this paper that the PSA should continue to approach this issue in a careful and reasoned manner, doing what it reasonably can to try to meet the professional needs of Research I University sociologists in the 21st century, but being mindful not to jeopardize what has made the PSA important and attractive to its growing number of other constituencies in recent years.