Laura M. Argys

Detracking America's schools: Equity at zero cost?

Schools across the country are ending the practice of grouping students based on ability, in part, because of research indicating that tracking hurts low-ability students without helping students of other ability levels. Using a nationally representative survey conducted by the National Center for Education Statistics, (NCES) we reexamine the impact of tracking on high school student achievement through the estimation of a standard education production function. This approach allows us to control for the possibility that track is correlated with factors such as class size and teacher education. In addition, we address the possibility that there are unobserved student or school characteristics that affect both achievement and track placement. Our results indicate that abolishing tracking in Americas schools would have a large positive impact on achievement for students currently in the lower tracks, but that this increase in achievement would come at the expense of students in upper-track classes.

For better or worse: Relationship status and body mass index

Recent increases in the incidence of obesity and declines in marriage have prompted policymakers to implement policies to mitigate these trends. This paper examines the link between these two outcomes. There are four hypotheses (selection, protection, social obligation and marriage market) that might explain the relationship between marital status transitions and changes in Body Mass Index (BMI). The selection hypothesis suggests that those with a lower BMI are more likely to be selected into marriage. The protection hypothesis states that married adults will have better physical health as a result of the increased social support and reduced incidence of risky behavior among married individuals. The social obligation hypothesis states that those in relationships may eat more regular meals and/or richer and denser foods due to social obligations which may arise because of marriage. Finally, the marriage market hypothesis indicates that when adults are no longer in the marriage market they may not maintain a healthy BMI because doing so is costly and they are in a stable union-or on the other hand, adults may enhance their prospects in the marriage market by losing weight. Taking advantage of longitudinal data and complete marriage histories in the National Longitudinal Survey of Youth 1979, we estimate individual fixed effects models to examine associations between the change in log BMI and the incidence of overweight and obesity, and changes in relationship status controlling for the effects of aging and other respondent characteristics. We find no support for the marriage protection hypothesis. Rather we find evidence supporting the social obligation and marriage market hypotheses-BMI increases for both men and women during marriage and in the course of a cohabiting relationship. Separate analyses by race and ethnicity reveal substantial differences in the response of BMI to relationship status across these groups.

The Impact of Child Support on Cognitive Outcomes of Young Children

We use the National Longitudinal Survey of Youth-Child data to address three questions. First, does the receipt of child support have beneficial effects for children with absent fathers apart from increasing income? Second, do the effects of child support differ when child-support awards and payments are made cooperatively as opposed to being court ordered? Third, are any positive effects of child support solely a product of unmeasured differences among fathers and families? Controlling for the socioeconomic characteristics of the child and family, we find some evidence that receipt of child support has a positive impact on children’s cognitive test scores over and above its contribution to total income. However, the effects vary by test, by race, and by reason for Father’s absence. Our results also indicate that the distinction between cooperative and noncooperative awards is important. Finally, our instrumental variables estimates show that the effects of child support persist after we control for unobserved characteristics of fathers and families.

New evidence on the relationship between substance use and adolescent sexual behavior.

Policymakers and the public have a clear interest in encouraging teens to delay becoming sexually active or, if they are sexually active, to use birth control. Many researchers have argued that reducing substance use among teens will accomplish both of these goals, yet work in this area has failed to control for unobservables that are potentially correlated with substance use and sexual behavior. Using a variety of estimation techniques and data from National Longitudinal Study of Adolescent Health, we estimate the effects of marijuana and alcohol use on two outcomes: the probability of being sexually active, and the probability of having sex without contraception. Our results highlight the importance of controlling for unobservables and indicate that the link between substance use and sexual behavior is much weaker than previously suggested.

The occurrence of preterm delivery is linked to pregnancy-specific distress and elevated inflammatory markers across gestation.

There is mounting evidence that stress during pregnancy can have detrimental effects on gestation and birth. Existing studies indicate that prenatal stress may increase levels of circulating inflammatory markers that are associated with prematurity and pregnancy complications, suggesting that stress-related changes in the cytokine milieu may increase the risk of poor pregnancy outcome. Previous studies, however, have not clearly connected stress during pregnancy to changes in inflammatory mediators and, in turn, to clinically-relevant outcomes such as premature delivery. The present study sought to directly connect prenatal stress and changes in inflammatory markers to preterm delivery and gestational age at birth (GAB). A sample of 173 women was recruited during the first trimester of pregnancy and followed through delivery. Overall stress, pregnancy-specific distress, and inflammatory markers were assessed early and later in pregnancy, and the predictive value of these measures for preterm birth and GAB was determined. There were significant differences in pregnancy-specific distress, IL-6, and TNF-α between women who delivered prematurely versus those who delivered at term, and elevated levels of pregnancy-specific distress, IL-6, and TNF-α were predictive of shortened GAB overall. Importantly, in many cases, the effects of overall stress and pregnancy-specific distress on GAB were mediated by levels of circulating inflammatory markers. Collectively, these data provide strong evidence that prenatal stress experiences can affect the timing of parturition via alterations in circulating inflammatory mediators, and underscore the need for ongoing research aimed at further understanding the mechanisms and effects of prenatal stress on maternal and infant health.

The Impact of Government Policies and Neighborhood Characteristics on Teenage Sexual Activity and Contraceptive Use

OBJECTIVES This study sought to examine the effects of government policies and neighborhood characteristics on adolescent female sexual behavior to better inform future public policy decisions. METHODS Using a bivariate probit model and National Survey of Family Growth data on women aged 15 through 19 years, we estimated the probabilities of their being sexually active and, if sexually active, of their using contraceptives. RESULTS Variables measuring the cost of obtaining an abortion are not good predictors of sexual activity or contraceptive use. However, the relationship between family planning availability and contraceptive use is statistically significant at conventional levels. CONCLUSIONS Policymakers seem to have little leverage with regard to influencing the decision to become sexually active, although increased access to family planning services may encourage responsible contraceptive behavior. Neighborhood context is an important determinant of adolescent female sexual behavior.

Enforcing divorce settlements: evidence from child support compliance and award modifications.

This paper uses an implicit contracting framework to understand the dynamic nature of divorce settlements and to analyze the determinants of noncompliance with child support awards. In addition to the standard economic variables that affect the noncustodial parent’s (NCP’s) ability to pay child support, our approach focuses on factors that may affect the NCP’s desire to pay, such as the ongoing relationship between the two parents and between the NCP and the children. We also examine the “state-contingent” nature of child support payments and explore the factors that lead to modifications in child support agreements. Using a longitudinal data set collected by the Stanford Child Custody Project, the empirical analysis provides documentation that compliance by noncustodial fathers can vary substantially from month to month. In addition, we find that even within a short period after divorce, a substantial minority of parents agree to make informal modifications to their divorce settlement in response to changes in economic circumstances and in custodial arrangements

Tracking in the United States: Descriptive statistics from NELS

Abstract Although there is a general sense among educational researchers that the practice of ability grouping is widespread, national descriptive statistics on the subject are scarce. This note presents data from the National Education Longitudinal Study of 1988 that suggest a sizeable majority of 8th and 10th grade students are tracked. Also, it is found that informal tracking patterns in the 8th grade and 10th grade seem to be broadly similar. Lastly, we note that students from low socioeconomic backgrounds, blacks, and Hispanics are more likely to be enrolled in lower track classes and less likely to be in upper track classes.

Can the Family Support Act Put Some Life Back into Deadbeat Dads?: An Analysis of Child-Support Guidelines, Award Rates, and Levels

Federal legislation mandates the use of child-support guidelines to improve adequacy and horizontal equity of child-support awards. Using state guideline formulas, and a sample of women drawn from the NLSY we compare the effects of guidelines on children born out of wedlock versus children whose parents divorced or separated. Our analyses indicate that guidelines increase the probability of child-support awards for children born out of wedlock. Guidelines also reduce variation in awards by eliminating outliers, not by equalizing awards across the entire distribution. Awards for high-income divorced or separated fathers fall substantially below the guideline amount.

Searching for Peer Group Effects: A Test of the Contagion Hypothesis

Using information on birth and kindergarten start dates to generate an exogenous measure of the relative age of a students peer group, we find that, controlling for age, females with older peers are more likely to use substances than females with younger peers. Because there is no reason to suspect that birth and kindergarten start dates should be correlated with the choice of school, the socioeconomic status of a childs peers, or neighborhood unobservables, we view our results with regard to females as providing support for the idea that peer behavior can be contagious.