On expected volumes of multidimensional confidence sets associated with the usual and adjusted likelihoods

We consider a general multiparameter set-up, where both the interest and the nuisance parameters are possibly vector valued. We derive an explicit higher order asymptotic formula to compare the expected volumes of confidence sets given by likelihood ratio statistics arising from the usual profile likelihood and various adjustments thereof. Our general framework also allows us to include highest posterior density regions, with approximate frequentist validity, in the study. The fact that our interest parameter is possibly vector valued complicates the derivation and warrants the development of special tools and techniques.     

Effects of Substance Abuse Central Intake on Treatment and Justice Costs

ABSTRACT

The cost-benefits of a central intake intervention for substance abuse treatment referrals were demonstrated using a transaction cost analysis on two cohorts of participants during the three-year initiative. Costs for clients receiving central intake services were compared with those just prior to the intervention's implementation. In order to study the relationship between substance abuse treatment costs and avoided criminal justice costs, data from three administrative data sets were used. Results indicate that clients receiving the central intake intervention had approximately a 58 percent decrease in costs compared to clients not receiving the intervention. The initiative produced opportunity cost savings to treatment, court, and correctional systems, with completion being crucial to opportunity cost savings.     

服务外包——社区矫正制度发展的可能模式

我国的社区矫正是与监禁矫正相对的行刑方式。社区矫正是一种充分利用社会资源,对社区范围内的假释、监(所)外执行、管制、剥夺政治权利、缓刑等罪犯进行针对性教育改造的手段和方法。目前社区矫正制度在基层司法实践中仍然面临着体制不顺、队伍不稳、资金不足、管理不到位等问题。针对基层司法实践过程中出现的问题,从社区矫正立法、管理机制、资金、队伍建设等方面提出了相应的建议——以服务外包的方式来解决问题。     

社区矫正疏议

社区矫正制度是源于英美等西方国家的一种新型的刑罚执行措施,它体现了刑罚执行制度由严趋宽的国际趋势。在促进罪犯重返社会、减轻监狱压力、避免轻犯交叉感染、合理配置行刑资源等方面有着重要意义。社区矫正自2002年在我国开始试点,目前已大范围试行。我们认为,社区矫正在其理论渊源、执行主体等方面还有许多问题亟待厘定和澄清。只有真正解决好这些问题,才能构建起适合我国国情的矫正制度,从而发挥这一新型刑罚执行措施的应有功效。     

Testing the Difference of Two Binomial Proportions: Comparison of Continuity Corrections for Saddlepoint Approximation

We carried out a simulation study based on the methodology of Newcombe (1998 Newcombe , R. G. ( 1998 ). Interval estimation for the difference between independent proportions: comparison of eleven methods . Statist. Med. 17 : 873 – 890 .[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) to compare tests for the difference of two binomial proportions by applying different continuity corrections on saddlepoint approximation to tail probabilities. In this article, we proposed a new continuity correction based on the least common multiple of two sample sizes. We evaluated that the best test should have the actual Type I error rates that are, on the whole, closest to α, but not exceeding α, where α is nominal level of significance.     

Bartlett corrections in beta regression models

We consider the issue of performing accurate small-sample testing inference in beta regression models, which are useful for modeling continuous variates that assume values in (0,1), such as rates and proportions. We derive the Bartlett correction to the likelihood ratio test statistic and also consider a bootstrap Bartlett correction. Using Monte Carlo simulations we compare the finite sample performances of the two corrected tests to that of the standard likelihood ratio test and also to its variant that employs Skovgaard's adjustment; the latter is already available in the literature. The numerical evidence favors the corrected tests we propose. We also present an empirical application.     

Extending the empirical likelihood by domain expansion

We extend the empirical likelihood beyond its domain by expanding its contours nested inside the domain with a similarity transformation. The extended empirical likelihood achieves two objectives at the same time: escaping the “convex hull constraint” on the empirical likelihood and improving the coverage accuracy of the empirical likelihood ratio confidence region to $O(n^{-2})$ . The latter is accomplished through a special transformation which matches the extended empirical likelihood with the Bartlett corrected empirical likelihood. The extended empirical likelihood ratio confidence region retains the shape of the original empirical likelihood ratio confidence region. It also accommodates adjustments for dimension and small sample size, giving it good coverage accuracy in large and small sample situations. The Canadian Journal of Statistics 41: 257–274; 2013 © 2013 Statistical Society of Canada