Somers' D and Kendall's tau-a are parameters behind rank or nonparametric statistics, interpreted as differences between proportions. Given two bivariate data pairs (X1, Y1) and (X2, Y2), Kendall’s tau-a parameter tau-XY is the difference between the probability that the two X–Y pairs are...

Students of racial and gender inequalities are often interested in knowing to what extent an observed group difference can be attributed to differences in returns to productive abilities (discrimination effect) or to differences in the average of productive abilities (endowment effect). The...

Data used in applied econometrics are typically nonexperimental in nature. This makes the assumption of exogeneity of regressors untenable and poses a serious identification issue in the estimation of economic structural relationships. As far as the source of endogeneity is confined to...

Most survival data are analyzed by using the Cox proportional hazards model (in Stata: the stcox command). Almost by definition, a proportion of the observations will be right-censored. Analysis of covariate effects in the Cox model is couched in terms of (log) hazard ratios, and the...

The method of multiple imputation provides an attractive approach to handling missing data in large studies. A variety of software is now available to produce multiply imputed (MI) datasets, and we have published a set of Stata commands a"MI tools" that facilitate the manipulation and analysis...

A major analytic challenge in epidemiological studies is the threat to validity and precision of conclusions raised by missing data. It is still commonly accepted practice to analyze data containing missing values by "complete-case" methods, where entire individuals are omitted from the analysis...

Do you find yourself regularly cutting and pasting your postestimation results, such as regression coefficients, into a spreadsheet? If so, you should consider trying to program wherever possible. Using Stata's matrix commands, this presentation will show you how to process postestimation...

Apart from collection of real pedigree data, it is also very important to have simulated pedigree data in genetic epidemiology research. The simulated data can be used to compare the efficiency of different statistical models and to investigate some phenomena that cannot be answered by the real...

Partially linear models are linear regression models where one component is allowed to vary nonparametrically. Generalized partially linear models generalize this case from linear regression to the quasi-likelihood setting of standard GLIMs, thus encompassing a larger class models including...

Not all firms contributed to Australia's impressive productivity growth in the 1990s. Some performed better than others, and entrants arrived even as incumbents exited. If firms make decisions on input demand and liquidation based on their productivity, the latter known to them but unobserved by...