Using West German panel data constructed from the 1988 and 1994/1995 wave of the DJI Familiensurvey, we analyze the stability
and determinants of individuals’ total desired fertility. We find considerable variation of total desired fertility across
respondents and across interviews. In particular, up to 50% of individuals report a different total desired fertility across
survey waves. Multivariate analysis confirms the importance of background factors including growing up with both parents,
having more siblings, and being Catholic for preference formation. Consistent with the idea that life course experiences provide
new information regarding the expected costs and benefits of different family sizes, the influence of background factors on
total desired fertility is strong early in life and weakens as subsequent life course experiences, including childbearing,
take effect. Accounting for unobserved individual heterogeneity, we estimate that an additional child may increase the total
desired fertility of women with children by 0.14 children, less than what conventional estimates from cross-sectional data
would have suggested. 相似文献
This article examines the gender, setting, and degree of the first authors of published articles in JMFT from 1990 to 1995. Findings reveal that men are the first authors of 67% of the articles and women, 33%. PhDs are first authors on 58% of the articles, and authors in university settings write 53% of the published articles. Thirty-nine percent of the articles published during this period were research; 26%, clinical; 16%, theory; and 14%, training. Surprising findings were that MSW authors had a higher acceptance rate than PhDs, and authors in training institutes had a higher acceptance rate than those in university settings. 相似文献
A class of distribution-free tests based on U-statistics has been proposed for testing the null hypothesis of independence against positive quadrant dependence. The tests are based on U-statistics and the Kendall's-tau test belongs to this class. 相似文献
There has been much debate in the managementliterature between neo-Darwinists (who believe in thenatural selection of populations of organizations) andadaptationists (who contend that changes in organization structure and behavior occur in response to theenvironment). The general thesis of neo-Darwinism isthat species are blindly selected for survival by theenvironment. The latest empirical support for the dominant neo-Darwinism perspective adopted bymost biologists is based primarily on the experimentsconducted by Salvador Luria who claims to haveconclusively demonstrated that genes mutate randomly.Recently, however, biologists have re-examined Luria sresearch methods and, after replications of hisexperiments, now question some aspects of the validityof his results. Moreover, there is now new researchwhich provides support for the earlier adaptationistposition, namely, the existence of evolutionary driversand directors existing within self-organizing systems.Of particular importance to the present study is the experimental indication thatself-organizing systems play a conscious role in theirown evolution. We propose that similar mechanisms orprocesses operate in organizational adaptation, thuspointing toward a theoretical modification ofneo-Darwinism that embraces both adaptation and naturalselection in a general, unified theory. 相似文献
The effects of reinforced pretraining on subsequent rule discovery were examined with college students as subjects. Levels of behavioral stereotypy observed during reinforced and non-contingent pretraining were compared. During pretraining subjects received reinforcement if they pressed two keys in a particular sequence. During the problem session pressing each key four times was a necessary condition for reinforcement, but each problem had additional different requirements for reinforcement. Subjects were asked to solve the problems by discovering the rule that determined whether or not they received reinforcement. Levels of stereotyped responding during pretraining were equivalent for contingently and non-contingently trained subjects. During the problem session contingently pretrained, non-contingently pretrained, and naive subjects required equal numbers of trials to solve problems and solved the same number of problems. The results suggest that behavioral stereotypy observed in this experimental preparation may be due to repeated exposure to the task. Differences between the results observed in this study and that of Schwartz (1982) and implications for the use of reinforcement procedures in applied settings are discussed.
Summary. Although it has been widely accepted since the 1960s that smoking cigarettes carries a substantial health risk, worldwide mortality from tobacco-related diseases is increasing rapidly at the beginning of the 21st century. To provide the motivation to control this epidemic there is a continuing and pressing need for information on the risks of tobacco consumption that is accurate, up to date, locally relevant and imaginatively presented. 相似文献
This article considers optimal prediction of the finite population distribution function under Gaussian superpopulation models, which allows auxiliary prior information to be incorporated into the estimation process. Large sample approximations for the variance of the optimal predictors are derived in some special important cases. A small scale Monte Carlo study illustrates comparisons between the optimal predictor and some others which are proposed in the literature. The conclusion is that the optimal predictor can be considerably more efficient in situations where the normal superpopulation model is adequate. 相似文献