This session offers an introduction to spatial econometrics using some user-written Stata commands. I will discuss the estimation and interpretation of the parameters in the cross-sectional spatial-autoregressive model. Data management issues pertaining to spatial-weighting matrices used in the...

Abstract not available.

Missing data is a pervasive issue in epidemiological, clinical, social, and economic studies. This presentation offers a brief overview of the conceptual issues raised by missing data, followed by an overview of some of the principled statistical methods of handling missing data that are...

Hierarchical datasets are commonly a product of the popular CSPro system developed by the U.S. Census Bureau. CSPro became widely popular and a de facto standard for data collection in many countries; some agencies supply data exclusively in CSPro format. While CSPro can export the data into...

Multiple imputation (MI) is a popular approach to handling missing data, and an extensive range of MI commands is now available in official Stata. A common problem is that of missing values in covariates of regression models. When the substantive model for the outcome contains nonlinear...

Previous trial has shown that starting ART therapy earlier (‘Early’) rather than waiting for onset of symptoms (‘Standard’) in HIV patients significantly decreases mortality. As a follow-up, researchers are interested in determining if ‘Early’ therapy significantly decreases time to...

Testing for the presence of autocorrelation in a time series is a common task for researchers working with time series data. The standard Q test statistic, introduced by Box and Pierce (1970) and refined by Ljung and Box (1978), is applicable to univariate time series and to testing for...

Inspired in the R library 'snow' and to be used in multicore CPUs, parallel implements parallel computing methods through an OS's shell scripting (using Stata in batch mode) to accelerate computations. By splitting the dataset into a determined number of clusters this module repeats a task...

Stata’s sem command includes the ability to estimate models with missing data using full information maximum likelihood estimation (FIML). One of the assumptions of FIML is that the data is at least missing at random (MAR), that is, conditional on other variables in the model, missingness is...

Fractals are some of the most beloved and recognizable mathematical objects studied. They have been traced as far back as Leibniz, but failed to receive rigorous examination until the mid-twentieth century with the many publications of Benoit Mandelbrot and the advent of the modern computer. The...