In many areas of social science, researchers want to use latent measures of ability as independent variables. Often cognitive test scores are used to measure this latent trait. Many social scientists do not model the measurement error inherent in the test score. I introduce the Mixed Effects...

A standard problem in social science attempts to better understand the large wage disparities between black and white workers in U. S. labor markets. Social scientists have conducted hundreds of studies of observed racial wage gaps, seeking to understand the extent to which they are driven by...