The Program for the International Assessment of Adult Competencies (PIAAC) is a multicycle international survey of adult skills and competencies sponsored by the Organization for Economic Cooperation and Development (OECD). The survey examines a range of basic skills in the information age and assesses these adult skills consistently across…

The Program for the International Assessment of Adult Competencies (PIAAC) is a multicycle survey of adult skills and competencies sponsored by the Organization for Economic Cooperation and Development (OECD). The survey examines a range of basic skills in the information age and assesses these adult skills consistently across participating…

Employing nested sequences of models is a common practice when exploring the extent to which one set of variables mediates the impact of another set. Such an analysis in the context of logistic regression models confronts two challenges: (1) direct comparisons of coefficients across models are generally biased due to the changes in scale that…

This case study presents an example of using a generalized linear model with a log-linear link to calculate an adjusted risk ratio to be able to assess the association between educational attainment and obesity in a cohort study of American adults. Both risk ratios and odds ratios can be calculated based on cohort study data, and risk ratios are…

In the United States, community colleges serve nearly half of the 18 million students enrolled in postsecondary education. However, it has only been the last decade or so where these public, two-year institutions have claimed substantial attention from the research community. This dissertation consists of three essays that focus on aspects of the…

In 2009, the National Center for Education Statistics (NCES) published a technical report titled "Indirect County and State Estimates of the Percentage of Adults at the Lowest Literacy Level for 1992 and 2003," (ED503830). NCES also published a corresponding online tool (http://nces.ed.gov/naal/estimates/index.aspx) that allows users to…

Researchers often compare the relationship between an outcome and covariate for two or more groups by evaluating whether the fitted regression curves differ significantly. When they do, researchers need to determine the "significance region," or the values of the covariate where the curves significantly differ. In analysis of covariance (ANCOVA),…

This paper uses data from the National Education Longitudinal Study to estimate the association between high school alcohol use and educational attainment measured around age 26. Initially, the effect of alcohol use on educational attainment is estimated using baseline probit models, which ignore the possibility that unmeasured determinants of…

When looking at the relationship between individual earnings and schooling, there are potential sources of bias which arise due to individual education choices; individuals of higher unobserved ability or with higher unobserved payoffs from schooling may for instance invest more in education. This paper reviews alternative models and estimation…