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231.
I present evidence that social capital reduces traffic accidents and related death and injury, using data from a 10‐year panel of 48 U.S. states. The econometric challenge is to distinguish the causal effects of social capital from bias resulting from its correlation with unobservable characteristics by state that influence road risks. I accomplish this by employing snow depth as an instrument, and by restricting attention to summertime accidents. My results show that social capital has a statistically significant and sizable negative effect on crashes, traffic fatalities, serious traffic injuries, and pedestrian fatalities that holds up across a range of specifications. (JEL R41, I18, Z13)  相似文献   
232.
Abstract

The present study was based on data collected (separately for husbands and wives) from 365 couples to determine levels of consensus on a series of variables related to the family forming process. Following Scheff (1967), consensus was operationalized as both agreement and coorientation in the marital dyad. The data generally indicated low levels of consensus on such variables as contraceptive efficacy, desired family size, child spacing, unwanted pregnancies, communication with spouse, and levels of alienation. The results are discussed within the framework of family planning and effective fertility control.  相似文献   
233.
An estimate of the change in intelligence in ten English education authorities during the past 10 years has been made by comparing the scores of complete year groups of 11-year-old children in 1947 with scores made by similar groups in the same test on an earlier occasion. The first test was taken by 31,728 children and the second by 28,505 children, boys and girls in approximately equal numbers.

For boys and girls together there was a fall of 0.0034 point of intelligence quotient per year, which was far from significant. In seven districts where we had separate scores for boys and girls on both occasions there was a significant fall in intelligence quotient of 0.0921 point per year amongst boys and a significant rise of 0.0921 point per year amongst girls.

The adventitious influences which might invalidate a comparison of the two sets of scores have been considered; they probably tend to depress the score at the second test.

A study of sex differences in attainment tests at 11 years and in intelligence tests at 13 years and later suggests that the scores of the boys in 1947 are underestimates of their ability, and that a truer measure of the trend of intelligence amongst the population is represented by the change in the girls' scores.

By assuming a certain parallelism between the present survey and that of the Scottish children, the rise in intelligence quotient of the latter is estimated at 0.0543 point per year.

A significant increase in the dispersion of intelligence test score of both boys and girls during the past 10 years has been recorded.  相似文献   
234.
A proportional hazards model was used to evaluate the association between ten categorical covariates and the risk of pre-term delivery for women having their first child and women in subsequent pregnancies. An adaptation of the model for use with grouped survival times made it possible to model foetal life times between 28 and 36 completed weeks of gestation for 67,000 Scottish singleton births in 1981. The use of the model was justified by testing time-dependent effects. For both groups of women age, and a history of abortion, were major factors associated with increased hazard. For women experiencing a second or higher-order birth a history of perinatal death was also associated with substantially increased hazard to the pregnancy.  相似文献   
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In this paper, a new test statistic is presented for testing the null hypothesis of equal multinomial cell probabilities versus various trend alternatives. Exact asymptotic critical values are obtained, The power of the test is compared with several other statistics considered by Choulakian et al (1995), The test is shown to have better power for certain trend alternatives.  相似文献   
238.
How educators handle conflicting views of Populism is important in engaging students in critical thinking.  相似文献   
239.
Abstract

This paper assesses the male contribution to contraceptive mismanagement and unwanted pregnancy. The subjects were 109 students at the University of Melbourne. A high incidence of risk-taking was reported, and almost one-fifth of the sexually experienced men stated that they had been involved in an unwanted pregnancy. A small group of these reported more than one such incident. The underlying reasons for poor contraceptive technique seemed to be related to two beliefs: that contraception is a female responsibility, and that sexual intercourse should be entirely spontaneous and unplanned.  相似文献   
240.
Abstract

We propose a cure rate survival model by assuming that the number of competing causes of the event of interest follows the negative binomial distribution and the time to the event of interest has the Birnbaum-Saunders distribution. Further, the new model includes as special cases some well-known cure rate models published recently. We consider a frequentist analysis for parameter estimation of the negative binomial Birnbaum-Saunders model with cure rate. Then, we derive the appropriate matrices for assessing local influence on the parameter estimates under different perturbation schemes. We illustrate the usefulness of the proposed model in the analysis of a real data set from the medical area.  相似文献   
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