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241.
Based on Dutch colonial registers (thombos), this paper reconstructs fertility for two districts in Ceylon, 1756–68. It overcomes challenges in data quality by establishing the outer bounds of plausible estimates in a series of scenarios. Among these, total fertility rates (TFRs) averaged 5.5 in one district, but only 2.7 in the other. These figures exclude the victims of infanticide, a custom noted in European travelogues between about 1660 and 1820. Sex ratios among children differed depending on the number of older siblings, and overall, 27?per cent of girls are missing in one district and 57?per cent in the other. There was little significant variation either in the TFR or the sex ratio by socio-economic status, suggesting that poverty was not a key factor in motivating infanticides. Instead, we argue that at least parts of Ceylon had a forward-looking culture of family planning in the eighteenth century, which was lost in subsequent decades.  相似文献   
242.
When are identity dilemmas—when people possess identities that conflict with one another and both are potentially stigmatizing—most likely to occur? Are they the result of generic social processes? A review of some of the extant research on “identity work” suggests that historical “misalignments” of culture and stratification, which we refer to as “lag,” create the greatest potential for stigma and the reproduction of inequalities. Lag is exacerbated by complex, intersecting axes of hierarchy, and amplified as symbolic environments globalize and subcultures multiply. Articulating culture and structure reveals how power plays out in interaction, and highlights the omnipresence of struggles for treatment as “fully human.” We consider whether “alignment” is even possible when multiple dimensions of social location intertwine, compete, and collide. Following Schwalbe and Mason‐Schrock (1996), we argue that “subcultural” or collective identity work that brings new meanings into dominant cultural narratives may offer the greatest hope, but in the interim all coping strategies are costly.  相似文献   
243.
244.
In this article, a new consistent estimator of Veram’s entropy is introduced. We establish the entropy test based on the new information namely Verma Kullback–Leibler discrimination methodology. The results are used to introduce goodness-of-fit tests for normal and exponential distributions. The root of mean square errors, critical values, and powers for some alternatives are obtained by simulation. The proposed test is compared with other tests.  相似文献   
245.
It is well known that in finance variances and covariances of asset returns move together over time. Recently, much interest has been aroused by an approach involving the use of the realized covariance (RCOV) matrix constructed from high-frequency returns as the ex-post realization of the covariance matrix of low-frequency returns. For the analysis of dynamics of RCOV matrices, we propose the generalized conditional autoregressive Wishart (GCAW) model. Both the noncentrality matrix and scale matrix of the Wishart distribution are driven by the lagged values of RCOV matrices, and represent two different sources of dynamics, respectively. The GCAW is a generalization of the existing models, and accounts for symmetry and positive definiteness of RCOV matrices without imposing any parametric restriction. Some important properties such as conditional moments, unconditional moments, and stationarity are discussed. Empirical examples including sequences of daily RCOV matrices from the New York Stock Exchange illustrate that our model outperforms the existing models in terms of model fitting and forecasting.  相似文献   
246.
In this paper we provide three nonparametric tests of independence between continuous random variables based on the Bernstein copula distribution function and the Bernstein copula density function. The first test is constructed based on a Cramér-von Mises divergence-type functional based on the empirical Bernstein copula process. The two other tests are based on the Bernstein copula density and use Cramér-von Mises and Kullback–Leibler divergence-type functionals, respectively. Furthermore, we study the asymptotic null distribution of each of these test statistics. Finally, we consider a Monte Carlo experiment to investigate the performance of our tests. In particular we examine their size and power which we compare with those of the classical nonparametric tests that are based on the empirical distribution function.  相似文献   
247.
The importance of good governance is praised by many academics and practitioners. The prominence of the subject suggests that measurement is important. However, setting out to measure the quality of governance empirically is controversial. Doubts regarding the feasibility and meaningfulness of this undertaking are widespread in the literature. Recognizing the potential caveats, the current article discusses a set of guidelines for structuring a theoretically sound local governance assessment tool based on the Decision Analysis and Operational Research literatures. The authors argue that using a multi-criteria model which employs several objective (quantitative and qualitative) indicators and relies on a participatory method to aggregate them is a suitable way of developing sensible Local Governance Indicators. The purpose here is to provide a detailed roadmap for any country (or region, or locality) willing to engage in the assessment of the quality of local governance. The real-world implementation of a model developed according to these guidelines could help raise awareness, promote good practices and increase the ‘governance literacy’ of citizens. By operationalizing good governance, analysts may also be able to further investigate the relationships between local governance practices and several socio-economic factors.  相似文献   
248.
Crime or disease surveillance commonly rely in space-time clustering methods to identify emerging patterns. The goal is to detect spatial-temporal clusters as soon as possible after its occurrence and to control the rate of false alarms. With this in mind, a spatio-temporal multiple cluster detection method was developed as an extension of a previous proposal based on a spatial version of the Shiryaev–Roberts statistic. Besides the capability of multiple cluster detection, the method have less input parameter than the previous proposal making its use more intuitive to practitioners. To evaluate the new methodology a simulation study is performed in several scenarios and enlighten many advantages of the proposed method. Finally, we present a case study to a crime data-set in Belo Horizonte, Brazil.  相似文献   
249.
In clinical trials, missing data commonly arise through nonadherence to the randomized treatment or to study procedure. For trials in which recurrent event endpoints are of interests, conventional analyses using the proportional intensity model or the count model assume that the data are missing at random, which cannot be tested using the observed data alone. Thus, sensitivity analyses are recommended. We implement the control‐based multiple imputation as sensitivity analyses for the recurrent event data. We model the recurrent event using a piecewise exponential proportional intensity model with frailty and sample the parameters from the posterior distribution. We impute the number of events after dropped out and correct the variance estimation using a bootstrap procedure. We apply the method to an application of sitagliptin study.  相似文献   
250.
Patient heterogeneity may complicate dose‐finding in phase 1 clinical trials if the dose‐toxicity curves differ between subgroups. Conducting separate trials within subgroups may lead to infeasibly small sample sizes in subgroups having low prevalence. Alternatively,it is not obvious how to conduct a single trial while accounting for heterogeneity. To address this problem,we consider a generalization of the continual reassessment method on the basis of a hierarchical Bayesian dose‐toxicity model that borrows strength between subgroups under the assumption that the subgroups are exchangeable. We evaluate a design using this model that includes subgroup‐specific dose selection and safety rules. A simulation study is presented that includes comparison of this method to 3 alternative approaches,on the basis of nonhierarchical models,that make different types of assumptions about within‐subgroup dose‐toxicity curves. The simulations show that the hierarchical model‐based method is recommended in settings where the dose‐toxicity curves are exchangeable between subgroups. We present practical guidelines for application and provide computer programs for trial simulation and conduct.  相似文献   
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