ESTIMATION OF A PROPORTION USING SEVERAL INDEPENDENT SAMPLES OF BINOMIAL MIXTURES

This paper considers a sequence of independent counts, with each count arising from a mixture of binomial distributions; the mixing distribution is fixed but the number of trials varies from count to count. In this common situation, an estimate of the underlying mean binomial proportion is needed. Two estimators are in general use: the arithmetic average and a weighted average of the observed proportions. Variances of the two estimators are compared and used to decide which estimator is preferred in a given context. The relative merits depend on the distribution of the proportions and the numbers of trials used.     

Attribution Style and Public Policy Attitudes Toward Gay Rights*

Objective. This study examines the influence of beliefs about the cause of homo‐sexuality on public policy attitudes concerning gay rights. Methods. Using data from the 1995 Oklahoma City Survey, we examine how beliefs about homosexuality as either a lifestyle choice or biological predisposition affect levels of support for gay rights. Results. Consistent with current debates over gay rights, our study reveals a strong positive association between biological attributions of homosexuality and support for gay rights. Opposition to gay rights is most pronounced among political conservatives, fundamentalist Protestants, persons with little or no favorable contact with gays, individuals who embrace negative stereotypes about gays, and persons with high scores on an index of homophobia. Conclusions. Etiological beliefs about homosexuality have a strong influence on public policy attitudes toward gay rights.     

Testing for efficiency and non-linearity in market and natural time series

Time series in traded markets such as currencies and securities involve supply/demand interaction, so they might be expected to contain distinctive and identifiable structures in comparison with data based on natural phenomena such as river flows or sunspots. This paper tests this proposition using standard econometric tests including variance ratios, modified rescaled range (R/S) ratios and BDS statistics together with non-linear prediction models. Four time series of each type (market or natural) are subject to a battery of tests for random walk and non-linear dependence. Surprisingly, the tests provide no reliable discrimination between the two types of series or reveal any embedded specification differences.     

保护区管理存在的问题与根源

要想实现保护区的有效管理,必须明确保护区管理存在的问题与根源.文章将保护区管理存在的各种具体问题抽象分类形成问题树,发现这些问题可以归结为权属、管理和政策三方面因素.这三大因素正是保护区管理的"症结所在",这一结论可为保护区管理政策与措施的制定提供参考意见.此外,保护区与周边社区的矛盾冲突问题,也是该文分析研究的一个重点内容.     

Model selection in spline nonparametric regression

A Bayesian approach is presented for model selection in nonparametric regression with Gaussian errors and in binary nonparametric regression. A smoothness prior is assumed for each component of the model and the posterior probabilities of the candidate models are approximated using the Bayesian information criterion. We study the model selection method by simulation and show that it has excellent frequentist properties and gives improved estimates of the regression surface. All the computations are carried out efficiently using the Gibbs sampler.     

Childlessness and Women Managers: ‘Choice’, Context and Discourses

Childlessness is increasing and might reflect acceptance of diversity, scope for individual choice and a creative ‘social imaginary’ about being feminine without being a mother. Childlessness also appears to have a contextual manifestation arising from the recognition that the long‐hours work culture in many organizations does not support appropriate parenting. A qualitative study of Australian managers reveals the contradictory discourses of childlessness around enlightened equality, maternalism, an elusive, ideal ‘work–life balance’ and individualism. The article explores a contextually nuanced, dynamic, generative theory of agency which does not hinge on the mother–child dyad, in explaining women managers’ choices to remain childless.