Lifecourse migration and redistribution of the elderly across U.S. regions and metropolitan areas

This analysis investigates the assertion that the baby-boom cohorts, by virtue of their large size and new lifecourse redistribution tendencies, are likely to initiate significant shifts in the distribution of the elderly population as these cohorts enter into the 65-and-older age categories. The author contends that cohorts' pre-elderly lifecourse migration patterns should be incorporated into studies of elderly population distribution shifts. 2 questions are addressed: will the new lifecourse migration patterns provide for a more deconcentrated redistribution of the baby-boom cohorts, both prior to and after their entry into the elderly age categories, than the lifecourse migration patterns followed by earlier cohorts; and will the new lifecourse distribution pattern lead, in the long run, to a significantly more deconcentrated distribution of the elderly population. The examination of these 2 questions focuses, largely, on redistribution across 9 broad regional and metropolitan area groupings defined on the basis of 3 census regions -- the North (combining the Northeast and Midwest census regions), the South, and the West -- and 3 categories of metropolitan status -- large metropolitan areas (those with 1980 populations exceeding 1 million), other metropolitan areas, and nonmetropolitan areas. The comparison of "new" versus "old" lifecourse migration patterns contrasts the census-based age-specific migration stream rates, registered over the 1975-80 period, with those registered over the 1965-70 period. Given the sharp and broad-based shift toward deconcentrated redistribution which characterized practically all segments of the population during the 1970s, it is assumed that the age-specific migration patterns observed over the 1975-80 period approximate the more deconcentrated redistribution tendencies which will be adopted by the baby-boom cohorts (and their successors) over the remainder of their lifecourse. The 1965-70 net migration rates point up the aggregate redistribution implications associated with the "old" lifecourse migration stream patterns. Among the rates for North large metropolitan areas, the only positive net migration is observed for the 25-29 age category; the greatest net outmigration rate is shown for the 65-69 age category. The rates for South nonmetropolitan areas are negative for all age categories under age 55, and most accentuated outmigration is shown during the young-adult years. The positive net migration exhibited for the older adult and post retirement ages reflects the low outmigration rates from nonmetropolitan areas during these ages and the slight peaking of immigration for these years. The results of this analysis imply that more attention should be devoted to migration, over the entirety of the lifecourse, in future studies of population redistribution.     

知识管理在供应链中的应用研究

随着知识经济时代的到来,知识管理的重要性日益突出.本文结合案例,试图将知识管理的基本理念和方法从单个企业拓展到整条供应链中,并提出了其中的一些问题和挑战.     

Preliminary test estimators of the parameters of simple linear model with measurement error

In this paper, we discuss the properties of preliminary test estimators (PTE) of the parameters of simple linear model with measurement error (ME model) when the slope of the linear model is suspected to be zero. Expressions of the bias, MSE and efficiencies are obtained under conditional as well as unconditional situations with known reliability coefficient. Conditional model results are compared to the standard model without measurement error. We also provide the unconditional model analysis in finite samples. Asymptotic theory under local alternatives is developed when the variance of measurement error or the ratio of the variance of the model error relative to the variance of the measurement error is known. Asymptotic expressions of bias and MSE of the estimators along with their efficiencies are obtained. In every case, it is shown that the measurement error tend to increase the variability of the estimators compared to the estimators without measurement error. Graphs and tables are provided to see these results and to determine optimum level of significance for minimum guaranteed efficiency. Received October 2001 RID="*" ID="*"  A. K. Md. E. Saleh is a Distinguished Research Professor and H. M. Kim is a Ph.D. candidate in the School of Mathematics and Statistics, Carleton University, Ottawa. Acknowledgment. The authors gratefully acknowledge the constructive suggestion of the referees to improve the paper. The research is supported by NSERC grant A3088.     

A CROSS-NATIONAL STUDY OF LEADERSHIP: PARTICIPATION AS A FUNCTION OF PROBLEM STRUCTURE AND LEADER POWER

This study explores the effects of task structure and leader power on participative leadership across Australian, African, Papua-New Guinea and Pacific Island managers. Managers in all national groups are more participative in situations of low structure and low power than for high structure and high power, respectively. Participation in situations of low structure and low power declines in the order: Australia, Africa, Papua-New Guinea, Pacific Islands. It is argued that this effect is an instrumental effect of managerial education, rather than being culturally determined. the Vroom-Yetton leadership methodology is used to measure participation levels. Subjects are a total of 150 middle-level managers attending management education courses.     

Status Implications of the Employment of Married Women in the United States

Abstract: The working wife as a factor in the determination of family status has been universally ignored by students of stratification. In this plea for investigation, it is suggested that the employment or married women could affect the system of stratification in the following ways: (1) making possible greater access to symbols of status; (2) implying that the husband has been unsuccessful in his own career; (3) identifying the wife with a particular occupation; and (4) identifying certain occupations with wives of high status.