Finite approximations in demography

Abstract Conventions exist for carrying out the arithmetic of population projection, finding the intrinsic rate of natural increase, and other demographic calculations. These are good approximations only for populations which are stationary or increasing very slowly. For rapidly increasing populations, which are presently the subject of much study, they can be readily improved. The improved formulae take account of the way in which the increase shifts the distribution of population within the five-year age group. A number of examples are given of the derivation of corrections to existing formulae. While the corrections are smaller than the error of the data available for most countries, such formulae are worth introducing in anticipation of better data. They in no way depend on machine computation, but the computer makes them especially easy to apply.     

Internships for women in higher education administration: springboards for success?

Administrative positions within higher education have been very homogeneous, reflecting an institutional culture in which males prevail. In an attempt to encourage women to consider alternatives in administrative positions, internship programs were developed to provide women with opportunities and a mechanism for career advancement. The purpose of this case study was to examine what women did as a result of participating in such an administrative internship program over a ten year time period at a comprehensive university. Interview data yielded consistent results that support existing literature about women in higher education. Trends were identified and recommendations suggested for encouraging more diversity within administrative positions in higher educational institutions. The findings of this study confirm the need for mentoring relationships for women in administrative positions.     

Genetic Studies of Pathological Gambling: A Review of Methodology and Analyses of Data from the Vietnam Era Twin Registry

Twin studies represent an important and powerful approach to estimating the relative contributions of environmental and genetic factors to the expression of psychiatric illnesses. In this article, we first explain the rationale for using large populations of monozygotic and dizygotic twin pairs to estimate genetic and environmental contributions to a disorder and the statistical modeling associated with this approach. We then review results from studies of the Vietnam Era Twin Registry that use this methodology to examine the etiology of pathological gambling (PG) behaviors. The results provide strong evidence for genetic contributions to the development of PG in men and set the foundation for future studies aimed at identifying the manner in which specific genes and environmental factors individually and in conjunction contribute to PG.     

The interaction of aging and 10 years of racing on ultraendurance running performance

The aim of this study was to examine the interaction between aging and 10 years of racing in endurance runners. Race-time data from 194 runners who had completed 10 consecutive 56-km ultramarathons were obtained. The runners were either 20.5 +/- 0.7, 30.0 +/- 1.0, 39.9 +/- 0.9, or 49.4 +/- 1.0 years old at their first race. Each runner's race speed was determined for each race over the 10 years. Data were analyzed using repeated-measures ANOVA, one-way ANOVA, and independent t tests and showed that performance improved and declined at greater rates for younger runners; younger runners had a greater capacity for improvement than older runners; approximately 4 years were required to reach peak racing speed, regardless of age; it was not possible to compete at peak speed for more than a few years; and the combined effects of 10 years of aging and racing neither improve nor worsen net performance. In conclusion, these data suggest that although these runners showed similar patterns of change in race speed over a 10-year period, the extent of change in performance was greater in younger than in older runners.     

Education's Effects on Psychological Well-Being

Data from the 1973–1978 General Social Surveys were usedto estimate, by means of multiple regression analysis, the effectsof years of school completed on eight dimensions of psychologicalwell-being for white men, white women, black men, and blackwomen. Estimates are provided of total effects, effects netof socioeconomic variables, and effects net of socioeconomicvariables, family situation, and frequency of attendance ofreligious services. There is little evidence for negative effects,the only statistically significant negative coefficient beingthat for satisfaction with community among white men. Thereis some evidence that education has positive effects on psychologicalwell-being in all subpopulalions except black men, the strongestevidence being for white women. Dummy variable regression estimatesof the effects of different increments of education indicategreater effects from four years of high school than from fouryears of college. There is tentative evidence that mothers'education may have an important positive effect on their offspring'spsychological well-being. . The data reported here are from the 1973–1978 GeneralSocial Surveys conducted by the National Opinion Research Center(James A. Davis, principal investigator) with funds from theNational Science Foundation. The authors are solely responsiblefor the analyses and interpretations presented here. The dataset was obtained from the Roper Center at the University ofConnecticut. We are indebted to the management of the San AntonioCollege Computer Center for providing computer time for thisproject.     

Validity Of Reported Date of Birth, Salary, and Seniority

This study reveals wide variations in actual vs. reported dateof birth, salary, and seniority. It suggests that invalidityis a specialized phenomenon, and that the direction and magnitudeof inaccurate responses are structurally related to characteristicsof the respondents.