Small-Sample Improved Seasonal Unit Root Tests for Trending and Breaking Series

In this article three unit root tests that allow for a break in both the seasonal mean and linear trend of the data are proposed. The tests, which can be seen as small-sample corrected versions of already known asymptotic tests, are shown to perform very well in simulations, and much better than their asymptotic counterparts.     

Small Area Estimation Using Estimated Population Level Auxiliary Data

Unit level linear mixed models are often used in small area estimation (SAE), and the empirical best linear unbiased prediction (EBLUP) is widely used for the estimation of small area means under such models. However, EBLUP requires population level auxiliary data, atleast area specific aggregated values. Sometimes population level auxiliary data is either not available or not consistent with the survey data. We describe a SAE method that uses estimated population auxiliary information. Empirical results show that proposed method for SAE produces an efficient set of small area estimates.     

Adolescent Religiosity and School Contexts*

Objectives. Schools serve as the primary social organizations for adolescents, structuring their lives and conveying a variety of skills, norms, and values, but relatively little is known about how schools influence the development of religious belief, attitudes, and behavior during adolescence. We explore how schools' religious norms, coupled with adolescents' pursuit of social status through conformity, affect public and private religiosity. Methods. Employing data from the National Longitudinal Study of Adolescent Health (Add Health), we use multilevel modeling to examine the impact of school context on adolescents' public and private religiosity. Results. We find that school norms are influential in shaping both public religious expressions and private devotional activities, but pursuit of social status is a motivation for change across religious contexts only of public religious activity. The effect of social status as a motivator of religious change was moderated by the strength of the adolescent's identification with the school, especially for private religiosity. Conclusions. Schools play a key role in the social development of adolescents, and students' religious beliefs and behaviors are influenced systematically and observably by the type of religious climate within the school.     

Emotional Climate in Families Experiencing Homelessness: Associations with Child Affect and Socioemotional Adjustment in School

This study examined associations among family‐level risks, emotional climate, and child adjustment in families experiencing homelessness. Emotional climate, an indirect aspect of emotion socialization, was indexed by parents’ expressed emotion while describing their children. Sociodemographic risk and parent internalizing distress were hypothesized to predict more negativity and less warmth in the emotional climate. Emotional climate was expected to predict observer‐rated child affect and teacher‐reported socioemotional adjustment, mediating effects of risk. Participants were 138 homeless parents (64 percent African‐American) and their four‐ to six‐year‐old children (43.5 percent male). During semi‐structured interviews, parents reported demographic risks and internalizing distress and completed a Five Minute Speech Sample about their child, later rated for warmth and negativity. Children's positive and negative affect were coded from videotapes of structured parent‐child interaction tasks. Socioemotional adjustment (externalizing behavior, peer acceptance, and prosocial behavior) was reported by teachers a few months later. Hypotheses were partially supported. Parent internalizing distress was associated with higher parent negativity, which was linked to more negative affect in children, and parent warmth was associated with children's positive affect. Neither emotional climate nor child affect predicted teacher‐reported externalizing behavior or peer acceptance, but parental negativity and male sex predicted lower prosocial behavior in the classroom. Future research directions and clinical implications are discussed.     

Correlated random effects regression analysis for a log-normally distributed variable

In regression analysis, it is assumed that the response (or dependent variable) distribution is Normal, and errors are homoscedastic and uncorrelated. However, in practice, these assumptions are rarely satisfied by a real data set. To stabilize the heteroscedastic response variance, generally, log-transformation is suggested. Consequently, the response variable distribution approaches nearer to the Normal distribution. As a result, the model fit of the data is improved. Practically, a proper (seems to be suitable) transformation may not always stabilize the variance, and the response distribution may not reduce to Normal distribution. The present article assumes that the response distribution is log-normal with compound autocorrelated errors. Under these situations, estimation and testing of hypotheses regarding regression parameters have been derived. From a set of reduced data, we have derived the best linear unbiased estimators of all the regression coefficients, except the intercept which is often unimportant in practice. Unknown correlation parameters have been estimated. In this connection, we have derived a test rule for testing any set of linear hypotheses of the unknown regression coefficients. In addition, we have developed the confidence ellipsoids of a set of estimable functions of regression coefficients. For the fitted regression equation, an index of fit has been proposed. A simulated study illustrates the results derived in this report.     

Of Sex and Romance: Late Adolescent Relationships and Young Adult Union Formation

To better understand the social factors that influence the diverse pathways to family formation young adults experience today, this research investigates the association between opposite‐gender relationships during late adolescence and union formation in early adulthood. Using data from the first and third waves of the Add Health (n= 4,911), we show that, for both men and women, there is continuity between adolescent and adult relationship experiences. Those involved in adolescent romantic relationships at the end of high school are more likely to marry and to cohabit in early adulthood. Moreover, involvement in a nonromantic sexual relationship is positively associated with cohabitation, but not marriage. We conclude that the precursors to union formation patterns in adulthood are observable in adolescence.