A comparison of the determinants of white and nonwhite interstate migration

The primary objective of this study is to present an explanation of the interstate migratory movements of white and nonwhite persons which occurred over the period 1955–1960. The study is similar to several other recent studies in that we estimate the magnitudes in which various factors have influenced interstate or interregional migration in the United States. It differs from earlier studies in two important respects. First, we estimate and compare the magnitudes in which certain factors have influenced both white and nonwhite interstate migration. Second, unlike previous studies, many of which have made “country-wide” estimates of the determinants of migration, we have disaggregated data to the state level and obtained white and nonwhite “migration elasticities” for every state. These elasticities are in turn used to test several additional hypotheses relating to racial and regional differences in the elasticities themselves. We argue that discrimination against nonwhites and/or differences in “social milieu” between South and nonsouth provide a unifying explanation for most of the observed differences in white and nonwhite migration elasticities.     

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     

Publisher Correction to: An integrated dietary assessment increases feeding event detection in an urban carnivore

Urban Ecosystems - The Publisher would like to correct the introduced formatting errors on the caption of Figure 1 and in the data in Table 2.     

FROM SHAME TO GAME IN ONE HUNDRED YEARS: AN ECONOMIC MODEL OF THE RISE IN PREMARITAL SEX AND ITS DE‐STIGMATIZATION

Societies socialize children about sex. This is done in the presence of peer‐group effects, which may encourage undesirable behavior. Parents want the best for their children. Still, they weigh the marginal gains from socializing their children against its costs. Churches and states may stigmatize sex, both because of a concern about the welfare of their flocks and the need to control the cost of charity associated with out‐of‐wedlock births. Modern contraceptives have profoundly affected the calculus for instilling sexual mores. As contraception improves there is less need for parents, churches, and states to inculcate sexual mores. Technology affects culture.     

Long-Term Trends In Migratory Behavior In A Developing Country: The Case of Mexico

Comparable lifetime migration relationships are estimated for Mexico for 1950, 1960, and 1970. Moreover, migration flows from each state to every other state are separately examined for each year. A number of significant changes over time are evident in the responsiveness of Mexican internal migrants to various socioeconomic stimuli, and appreciable differences are also evident across space. Moreover, a threshold is observed such that up to about 340 miles higher origin earnings deter migration, but beyond this distance higher earnings actually encourage migration.     

Sleep hygiene practices and sleep duration in rotating-shift shiftworkers

Alcohol, caffeine and tobacco intake, exercise, activities on going to bed, and sleep-enhancing measures were assessed in 72 rotating-shift shiftworkers to determine whether these variables differ following day shifts and night-shifts, and which are related to sleep duration. Only alcohol intake and exercise prior to sleep, and feeling drowsy when retiring, differed following the night-shift. Workers generally followed recommendations concerning alcohol intake, sleeping immediately on retiring, and exercising, but acted contrary to recommendations concerning caffeine and nicotine intake. The only behaviour clearly associated with poor sleep was smoking, which reduced sleep duration.     

Efficiency of reduced logistic regression models

One feature of the usual polychotomous logistic regression model for categorical outcomes is that a covariate must be included in all the regression equations. If a covariate is not important in all of them, the procedure will estimate unnecessary parameters. More flexible approaches allow different subsets of covariates in different regressions. One alternative uses individualized regressions which express the polychotomous model as a series of dichotomous models. Another uses a model in which a reduced set of parameters is simultaneously estimated for all the regressions. Large-sample efficiencies of these procedures were compared in a variety of circumstances in which there was a common baseline category for the outcome and the covariates were normally distributed. For a correctly specified model, the reduced estimates were over 100% efficient for nonzero slope parameters and up to 500% efficient when the baseline frequency and the effect of interest were small. The individualized estimates could have efficiencies less than 50% when the effect of interest was large, but were also up to 130% efficient when the baseline frequency was large and the effect of interest was small. Efficiency was usually enhanced by correlation among the covariates. For an underspecified reduced model, asymptotic bias in the reduced estimates was approximately proportional to the magnitude of the omitted parameter and to the reciprocal of the baseline frequency.