Stata uses numeric quantities as logical values, and provides logical operators (&, |, ~) to build expressions from basic entities. These operators can be regarded as faulty when missing values are present in the operands. In this context, missing is equivalent to true, which is often not the...

While much has been made of multi-level models, and specialized software for such models, in many cases standard methods can be used in estimating these models. Use of such standard methods is faster and easier, in many cases, than use of specialized software; futher, use of standard methods...

Although Stata has made estimating regression models for categorical and count outcomes virtually as fast and easy as estimating the familiar regression model for continuous outcomes, interpreting the results from the former is complicated by the nonlinear relationship between the independent...

This presentation will cover a collection of statistics teaching tools written in Stata. These programs involve demonstrations or simulations of various statistical topics that are used both in the classroom and individually by the students. Topics include probability (coin, dice, box models),...

Longitudinal data are commonly collected in experimental and observational studies, where both disease and risk factors are measured at different repeated times. The goal of this project is to compare analyses performed using Stata, SPlus and SAS under two different families of distributions:...

Most of the data sets available through the National Center for Education Statistics (NCES) are based on complex sampling designs involving multi-stage sampling, stratification, and clustering. These complex designs require appropriate statistical techniques to calculate the variance. Stata...

I receive several (ir)regular deliveries of data files for the on-going development of a panel data set. Both the delivering agency systems and the targets of our research group change over time -- by the hour and/or by the year. I need to be able to identify from the filenames which Stata .dta...

Circular data are a large class of directional data, which are of interest to scientists in many fields, including biologists (movements of migrating animals), meteorologists (winds), geologists (directions of joints and faults) and geomorphologists (landforms, oriented stones). Such examples...

Many researchers need to estimate panel data models in which either the idiosyncratic term is autocorrelated or the model includes a lagged dependent variable. This talk will review some of the estimation and inference methods that have appeared in the econometric literature to deal with these...

Some data sets contain observations corresponding to pairs of entities (people, companies, countries, etc.). Conceptually, each observation corresponds to a cell in a square matrix, where the rows and columns are labelled by the entities. For example, consider a square matrix where the rows and...