Detecting selection bias,using propensity score matching,and estimating treatment effects: an application to the private returns to a master’s degree

Most research in the area of higher education is plagued by the problem of endogeneity or self-selection bias. Unlike ordinary least squares (OLS) regression, propensity score matching addresses the issue of self-selection bias and allows for a decomposition of treatment effects on outcomes. Using panel data from a national survey of bachelor’s degree recipients, this approach is illustrated via an analysis of the effect of receiving a master’s degree, in various program areas, on wage earning outcomes. The results of this study reveal that substantial self-selection bias is undetected when using OLS regression techniques. This article also shows that, unlike OLS regression, propensity score matching allows for estimates of the average treatment effect, average treatment on the treated effect, and the average treatment on the untreated effect on student outcomes such as wage earnings.     

Behavioral profiles of children with epilepsy: Parent and teacher reports of emotional,behavioral, and educational concerns on the BASC‐2

The Behavior Assessment Scale for Children – Second Edition (BASC‐2) was administered to 108 parents and 37 teachers of children with epilepsy (mean age of 10.6 years; 51% female, 49% male). Results demonstrated high mean scores on the Atypicality, Attention Problems, Withdrawal, and Adaptive Skills scales and a high percentage of At‐Risk or Clinically Significant scores on the majority of scales. Ratings were correlated with level of functioning, age of onset, and number of antiepileptic medications. In addition, children with poor seizure control had higher ratings on the Depression, Somatization, and Withdrawal scales, and children with temporal lobe seizures had higher scores on the Depression scale. These results confirm a high rate of behavioral concerns in children with epilepsy. © 2008 Wiley Periodicals, Inc.