Adapting private family time in child protective services decision-making processes

The Family Group Conference (FGC) is grounded in a rights-based framework, whereby children and their families have the right and responsibility to be primary decision-makers when child protection issues arise, and the statutory agency has the responsibility to convene the entitled members of the family network to lead the decision-making. A distinct core component of FGC—private family time (PFT)—allows families to discuss the information and formulate their responses and plans privately during conferencing. This paper describes how a large child welfare agency in the United States adapted PFT in two ways: (1) including a parent advocate (PA) and (2) abbreviating the amount of time allowed for this discussion. Given the lack of empirical research on the PFT component, this qualitative exploratory study sought to understand the functions and perceived impacts of PA-supported PFT during initial child protective services (CPS) conferences at which decisions of child removal or placement were being contemplated. PFT served multiple beneficial functions and impacted families in several positive ways: families gained greater awareness of safety concerns, felt empowered and confident in the preferred safety and service plan, became increasingly engaged and involved in the case decision-making process and ultimately felt less apprehensive.     

Optimal Contracts when Enforcement is a Decision Variable

This paper analyzes choice‐theoretic costly enforcement in an intertemporal contracting model with a differentially informed investor and entrepreneur. An intertemporal contract is modeled as a mechanism in which there is limited commitment to payment and enforcement decisions. The goal of the analysis is to characterize the effect of choice‐theoretic costly enforcement on the structure of optimal contracts. The paper shows that simple debt is the optimal contract when commitment is limited and costly enforcement is a decision variable (Theorem 1). In contrast, stochastic contracts are optimal when agents can commit to the ex‐ante optimal decisions (Theorem 2). The paper also shows that the costly state verification model can be viewed as a reduced form of an enforcement model in which agents choose payments and strategies as part of a perfect Bayesian Nash equilibrium.     

Bayesian parametric accelerated failure time spatial model and its application to prostate cancer

Prostate cancer (PrCA) is the most common cancer diagnosed in American men and the second leading cause of death from malignancies. There are large geographical variation and racial disparities existing in the survival rate of PrCA. Much work on the spatial survival model is based on the proportional hazards (PH) model, but few focused on the accelerated failure time (AFT) model. In this paper, we investigate the PrCA data of Louisiana from the Surveillance, Epidemiology, and End Results program and the violation of the PH assumption suggests that the spatial survival model based on the AFT model is more appropriate for this data set. To account for the possible extra-variation, we consider spatially referenced independent or dependent spatial structures. The deviance information criterion is used to select a best-fitting model within the Bayesian frame work. The results from our study indicate that age, race, stage, and geographical distribution are significant in evaluating PrCA survival.     

Some applications of nonlinear and non-Gaussian state–space modelling by means of hidden Markov models

Nonlinear and non-Gaussian state–space models (SSMs) are fitted to different types of time series. The applications include homogeneous and seasonal time series, in particular earthquake counts, polio counts, rainfall occurrence data, glacial varve data and daily returns on a share. The considered SSMs comprise Poisson, Bernoulli, gamma and Student-t distributions at the observation level. Parameter estimations for the SSMs are carried out using a likelihood approximation that is obtained after discretization of the state space. The approximation can be made arbitrarily accurate, and the approximated likelihood is precisely that of a finite-state hidden Markov model (HMM). The proposed method enables us to apply standard HMM techniques. It is easy to implement and can be extended to all kinds of SSMs in a straightforward manner.     

Choosing Priors for Constrained Analysis of Variance: Methods Based on Training Data

Abstract. This article combines the best of both objective and subjective Bayesian inference in specifying priors for inequality and equality constrained analysis of variance models. Objectivity can be found in the use of training data to specify a prior distribution, subjectivity can be found in restrictions on the prior to formulate models. The aim of this article is to find the best model in a set of models specified using inequality and equality constraints on the model parameters. For the evaluation of the models an encompassing prior approach is used. The advantage of this approach is that only a prior for the unconstrained encompassing model needs to be specified. The priors for all constrained models can be derived from this encompassing prior. Different choices for this encompassing prior will be considered and evaluated.     

Asymptotically optimal Berry-Esseen-type bounds for distributions with an absolutely continuous part

Recursive and closed form upper bounds are offered for the Kolmogorov and the total variation distance between the standard normal distribution and the distribution of a standardized sum of n independent and identically distributed random variables. The method employed is a modification of the method of compositions along with Zolotarev's ideal metric. The approximation error in the CLT obtained vanishes at a rate O(n^−k/2+1), provided that the common distribution of the summands possesses an absolutely continuous part, and shares the same k−1 (k?3) first moments with the standard normal distribution. Moreover, for the first time, these new uniform Berry-Esseen-type bounds are asymptotically optimal, that is, the ratio of the true distance to the respective bound converges to unity for a large class of distributions of the summands. Thus, apart from the correct rate, the proposed error estimates incorporate an optimal asymptotic constant (factor). Finally, three illustrative examples are presented along with numerical comparisons revealing that the new bounds are sharp enough even to be used in practical statistical applications.     

提前期、构建成本和短缺量拖后率均可控的EOQ模型

传统库存模型通常将提前期和构建成本视为不可控制。事实上可以通过追加投资缩短提前期和降低构建成本。缺货期间,为减少订单丢失量和补偿顾客的损失,供应商会给予一定的价格折扣。现实库存系统中,容易得到需求的期望值和标准差,但较难得到其分布规律。基于此,考虑短缺量拖后率与价格折扣和缺货期间库存水平相关,提出了一种需求为任意分布且提前期和构建成本均可控的EOQ模型,证明了模型存在唯一最优解,给出了一种寻优算法。数值仿真分析表明,一般情况下,压缩提前期和降低构建成本能降低订购批量和安全库存,降低库存总成本;短缺量拖后系数和缺货概率对库存总成本影响较大,企业应尽量降低缺货概率,尤其在短缺量拖后系数较小时。     

Time use surveys,social practice theory,and activity connections

Social practice theory (SPT) represents a growing body of research that takes the ‘doings and sayings’ (social practices) of everyday life as its core unit of enquiry. Time use surveys (TUS) represent a substantial source of micro-data regarding how activities are performed across the 24-h day. Given their apparent complementarities, we ask why TUS have not been utilised more extensively within SPT-inspired research. We advance two contentions: (1) ontological tensions obscure the relevance of TUS data in addressing core SPT research questions, and (2) SPT concepts do not readily translate for application in TUS analysis. In response, we operationalise Schatzki's (2019) concepts of activity events and chains to explore types and forms of temporal activity connection. Using TUS data we examine three activity events: sleeping, reading, and eating. Two types of temporal activity connection (sequence and synchronisation) are identified, together with four forms of connectivity (degrees of uniformity/diversity, sequential directionality, time-varying connections, and symmetrical/asymmetrical relationships). While practices cannot be reduced to activity connections, we argue that this analytical approach offers a systematic basis for examining the ways in which activities combine to underpin the organisation of social practices. Further analysis to compare activity connections across practices, between different groups of practitioners, and over time would offer a valuable resource to empirically examine claims regarding core processes of societal change. We further contend that SPT approaches offer insights for time use research by providing a framework capable of recognising that activities are dynamic and variable rather than homogeneous and stable categories.     

苏共党内特权阶层究竟产生于何时

关于原苏共党内特权阶层产生的时间问题,国内学术界有产生于斯大林时期说、产生于赫鲁晓夫时期说以及产生于勃列日涅夫时期说三种不同的版本。本文作者通过大量史实论证了苏共党内特权阶层产生于斯大林时期说的正确性与可信性。     

The Apparent‐Time Construct and stable variation: Final /z/ devoicing in northwestern Indiana1

As real‐time language data becomes increasingly available for sociolinguistic research, a growing number of studies are benefitting from it in order to study language changes in progress, some of which even explicitly seek to scrutinize the Apparent‐Time Construct itself. Vanishingly few real‐time studies, however, have focused specifically on stable sociolinguistic variables, leaving an important gap in our understanding of the Apparent‐Time Construct's abilities to model real‐time facts. In an effort to address this gap, the present study analyzes a presumably stable sociolinguistic variable – final /z/ devoicing – in extreme northwestern Indiana through real and apparent time. A series of Varbrul analyses indicate that this variable is, indeed, stable throughout the 20 years of real time covered by the data and that its stability is successfully modeled in apparent time. Additionally, similarities in /z/ devoicing between this community and some other communities where it has also been studied are identified and discussed.