Multivariate association test for rare variants controlling for cryptic and family relatedness

In genetic studies of complex diseases, multiple measures of related phenotypes are often collected. Jointly analyzing these phenotypes may improve statistical power to detect sets of rare variants affecting multiple traits. In this work, we consider association testing between a set of rare variants and multiple phenotypes in family‐based designs. We use a mixed linear model to express the correlations among the phenotypes and between related individuals. Given the many sources of correlations in this situation, deriving an appropriate test statistic is not straightforward. We derive a vector of score statistics, whose joint distribution is approximated using a copula. This allows us to have closed‐form expressions for the p‐values of several test statistics. A comprehensive simulation study and an application to Genetic Analysis Workshop 18 data highlight the gains associated with joint testing over univariate approaches, especially in the presence of pleiotropy or highly correlated phenotypes. The Canadian Journal of Statistics 47: 90–107; 2019 © 2018 Statistical Society of Canada     

To Regulate Or Not To Regulate? Early Evidence on the Means Used Around the World to Promote Gender Diversity in the Boardroom

Despite the growing public concern in recent years about the place of women in business, gender diversity in corporate governance has made little progress. As a consequence, the issue has captured the worldwide attention of policymakers. Several countries are currently adopting or considering the adoption of laws or regulations to promote gender diversity on corporate boards. The purpose of this paper is to compare the effectiveness of using legislative or regulatory means to increase female representation instead of allowing firms to voluntarily fix their own non‐legally binding targets. We find that the relation between gender diversity and performance is positive in countries using the voluntary approach while it is negative in countries using the regulatory approach. We conclude that public policy aimed at increasing the number of women on corporate boards should be introduced gradually and voluntarily rather than quickly and coercively to avoid sub‐optimal board composition.