Multivariate Kendall's tau for change‐point detection in copulas

Statistical procedures for the detection of a change in the dependence structure of a series of multivariate observations are studied in this work. The test statistics that are proposed are $L_1$ , $L_2$ , and $L_{\infty }$ distances computed from vectors of differences of Kendall's tau; two multivariate extensions of Kendall's measure of association are used. Since the distributions of these statistics under the null hypothesis of no change depend on the unknown underlying copula of the vectors, a procedure based on the multiplier central limit theorem is used for the computation of p‐values; the method is shown to be valid both asymptotically and for moderate sample sizes. Alternative versions of the tests that take into account possible breakpoints in the marginal distributions are also investigated. Monte Carlo simulations show that the tests are powerful under many scenarios of change‐point. In addition, two estimators of the time of change are proposed and their efficiency is carefully studied. The methodologies are illustrated on simulated series from the Canadian Regional Climate Model. The Canadian Journal of Statistics 41: 65–82; 2013 © 2012 Statistical Society of Canada     

Textbook Affordability in the Time of COVID-19

Abstract

This article provides a background of the textbook affordability problem affecting students attending United States higher education institutions, both prior to and during the 2019 novel coronavirus disease (COVID-19) pandemic, as well as potential solutions to the problem. Solutions discussed include the availability of open materials in online repositories, publisher responses like inclusive access, institutional incentive programs, and initiatives by library consortia or other statewide programs. The responses of various stakeholders to make textbooks accessible to students during the pandemic are also covered.     

Real Jobs: the perspectives of workers with learning difficulties

In a central New Zealand region, 14 people with learning difficulties who were identified by disability agencies as successfully employed were interviewed. Semistructured interviews with the paid workers covered topics such as getting and learning their work, pay, choices about social opportunities and career paths. Interviews were transcribed and constant discussion, and challenging of qualitative data identified the following themes: the effect of paid work on lifestyles, how other people were important for support and workers' aspirations for the future. The effect of paid work has meant major changes for a few people by becoming independent of the benefit system and buying their own home. For other workers, it meant having to learn to use the public transport system and choosing their own social activities. Workers' perspectives were used to provide better understanding of the supports needed by adults with learning difficulties to enhance their employment rates and careers in the paid workforce.     

Of Journal Editors and Editorial Boards: Who Are the Trailblazers in Increasing Editorial Board Gender Equality?

Female academics continue to be under‐represented on the editorial boards of many, but not all, management journals. This variability is intriguing, because it is reasonable to assume that the size of the pool of female faculty available and willing to serve on editorial boards is similar for all management journals. This paper therefore focuses on the characteristics of the journal editors to explain this variability; journal editors or editors‐in‐chief are the most influential people in the selection of editorial board members. The authors draw on social identity and homosocial reproduction theories, and on the gender and careers literature to examine the relationship between an editor's academic performance, professional age and gender, and editorial board gender equality. Longitudinal data are collected at five points in time, using five‐year intervals, from 52 management journals. To account for the nested structure of the data, a three‐level multilevel model was estimated. Overall, it is found that the prospects of board membership improve for women when editors are high‐performing, professionally young or female. The authors discuss these findings and their implications for management journals with low, stagnant or declining representation of women in their boards.     

Parenthood and Well-Being: The Moderating Role of Leisure and Paid Work

This study contributes to our knowledge on the association between parenthood and psychological well-being by examining whether pre-parenthood lifestyles (leisure and paid work) moderate the transition to parenthood. We expected that people with less active lifestyles would find it easier to adapt to the demands of parenthood. Using eleven waves of the Swiss Household Panel (N = 1332 men and 1272 women; 1999–2008, 2010), fixed effects models are estimated for men and women separately. Results show that—on average—parenthood was not associated with well-being for men, whereas it increased well-being for women. As expected, the well-being premium/cost to parenthood was contingent upon individuals’ lifestyle before the transition to parenthood. For men, parenthood reduced well-being, but only if they frequently participated in leisure before the birth of the child. For women, motherhood had a beneficial effect on well-being but this effect was weaker for women who combined leisure with working long hours before motherhood.     

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.     

Decision-Making and Evidence in Direct Practice

This article presents the results of research designed to explore decision-making by direct practitioners in selected non-profit human service settings. Forty interviews were conducted with workers at front-line, supervisory and higher-management levels. The research questions included; what sources of information are used in decision-making, what variables enhance or impede utilization of evidence-based knowledge in decision-making and what would be important resources for improving availability, access and utilization of evidence-based knowledge in decision-making? Our results indicate that respondents relied most heavily on experience; on their professional values and beliefs, and on an empathic understanding of their clients’ uniqueness. Compared to these sources of information use of research and the professional literature were less enthusiastically endorsed.