目前的统计形势(上)

统计学有三个相互关联的支柱 :概率数学、调查设计的一般原理、调查分析和解释的一般原理 ;统计推断的形式原理是第三支柱的一部分 ;现代概率理论的发展已在现代数学中占有丰富多采的篇章 ;调查设计与实验之间在原则上有重大差别 ;新分析方法有很大发展 ,许多统计工作无疑与各种具体测度有关 ;推断的形式理论 ,争论主要集中在概率推理方面 ;政府统计学家与社会科学研究工作者之间需要合作 ;最近 1 0多年统计思想创新进入一个新时期。     

Estimation of long-term trends and variation in avian survival probabilities using random effects models

We obtained banding and recovery data from the Bird Banding Laboratory (operated by the Biological Resources Division of the US Geological Survey) for adults from 129 avian species that had been continuously banded for > 24 years. Data were partitioned by gender, banding period (winter versus summer), and by states/provinces. Data sets were initially screened for adequacy based on specific criteria (e.g. minimum sample sizes). Fifty-nine data sets (11 waterfowl species, the Mourning Dove and Common Grackle) met our criteria of adequacy for further analysis. We estimated annual survival probabilities using the Brownie et al. recovery model {St, ft} in program MARK. Trends in annual survival and temporal process variation were estimated using random effects models based on shrinkage estimators. Waterfowl species had relatively little variation in annual survival probabilities (mean CV = 8.7% and 10% for males and females, respectively). The limited data for other species suggested similar low temporal variation for males, but higher temporal variation for females (CV = 40%). Evidence for long-term trends varied by species, banding period and sex, with no obvious spatial patterns for either positive or negative trends in survival probabilities. An exception was Mourning Doves banded in Illinois/Missouri and Arizona/New Mexico where both males (slope = -0.0122, se = 0.0019 and females (slope = -0.0109 to -0.0128, se = 0.0018 -0.0032) exhibited declining trends in survival probabilities. We believe our approach has application for large-scale monitoring. However, meaningful banding and recovery data for species other than waterfowl is very limited in North America.     

Of Roots and Wings: Letting Go of the College‐Bound Child

This article examines how parents experience the process of “letting go” of their college‐bound children. The focus of our analysis is on how the parents evaluate the meanings of their children's leaving home and adopt strategies to facilitate the process for both themselves and the departing child. Our analysis is based on interviews with thirty sets of parents. The interview materials allowed us to recognize and then parse the paradoxical task faced by parents of fostering “attached individuation” for both themselves and their children. We address four broad and persistent themes that emerged from our conversations with parents. First, we consider how parents manage the range of sometimes‐conflicting emotions generated by the letting go process. Second, we analyze the content of parents' worries as a good unobtrusive measure of how they understand the transition to college as a ritual marker in their children's lives. Third, we show how negotiations about geography—about proper distance from home—in choosing a college reflect efforts to impose a measure of gradualism into the letting go process. Fourth, we report on how parents theorize the impact of a child's departure on family relationships in general.     

Fully-Revealing Equilibria of Multiple-Sender Signaling and Screening Models

Models of incomplete information have played a major role in the fields of political science and political economy. The models have almost exclusively been signaling models, and their substantive focus is frequently on situations in which the extensive form is not dictated by institutional requirements or procedures. We explore the relation between multiple-sender signaling games and the corresponding screening or mechanism design games without transfers and establish an equivalence result. If there is a fully-revealing equilibrium in the signaling game there is also a full-information optimal mechanism that yields the principal’s optimal policy in every state. The converse, that fully-revealing equilibria exist in the signaling game if a full-information optimal mechanism exists, is true if and only if the mechanism involves only the selection of policies that are optimal for some belief about the state. We also present two straightforward sufficient conditions for the existence of full-information optimal mechanisms. When either holds, fully-revealing equilibria in the signaling and screening games exist. The perceived advantage of the signaling over the screening approach – that no commitment by the principal is assumed – may be over-stated as flexibility in specifying off the path beliefs can mimic commitment.     

Frank Parsons's Enablers: Pauline Agassiz Shaw,Meyer Bloomfield,and Ralph Albertson

Frank Parsons was not the 1st American to recognize or address the need for vocational guidance. Why he, rather than his predecessors, is credited with initiating the field can be attributed to the largely overlooked contributions of 3 other persons: Pauline Agassiz Shaw, Meyer Bloomfield, and Ralph Albertson. The author calls attention to the contributions of these 3 remarkable individuals, and several others who supported them, in enabling and perpetuating Parsons's work.     

Accelerated life regression modelling of dependent bivariate time‐to‐event data

To analyze bivariate time‐to‐event data from matched or naturally paired study designs, researchers frequently use a random effect called frailty to model the dependence between within‐pair response measurements. The authors propose a computational framework for fitting dependent bivariate time‐to‐event data that combines frailty distributions and accelerated life regression models. In this framework users can choose from several parametric options for frailties, as well as the conditional distributions for within‐pair responses. The authors illustrate the flexibility that their framework represents using paired data from a study of laser photocoagulation therapy for retinopathy in diabetic patients.