Stata 11.1 is now available as a free update to Stata 11. It adds several new features and extensions to existing features. If you have Stata 11, just type update all in Stata, and then type update swap. Or select Help from the main Stata menu, then select Official Updates and follow the instructions in the resulting Viewer window.
Here are some of the new features in Stata 11.1:
Multiple imputation. The mi command now officially supports fitting panel-data and multilevel models.
Truncated count-data models. New commands tpoisson and tnbreg fit models of count-data outcomes with any form of left truncation, including truncation that varies by observations.
Mixed models. Linear mixed (multilevel) models have new covariance structures for these residuals: exponential, banded, and Toeplitz.
Probability predictions. predict after count-data models, such as poisson and nbreg, can now predict the probability of any count or any count range.
Survey bootstrap. Estimation commands can now estimate survey bootstrap standard errors (SEs) using user-supplied bootstrap replicate weights.
Survey SDR weights. Successive difference replicate (SDR) weights are now supported when estimating with survey data. These weights are supplied with many datasets from the United States Census Bureau.
Concordance. estat concordance adds a new measure of concordance, Gönen and Heller’s K, that is robust in the presence of censoring.
Survey GOF. Goodness-of-fit (GOF) tests are now available after probit and logistic estimates on survey data.
Robust SEs. Cluster–robust SEs have been added to xtpoisson, fe.
Survey CV. The coefficient of variation (CV) is now available after estimation with survey data.
Estimation formatting. Numerical formats can now be customized on regression results. You can set the number of decimal places for coefficients, SEs, p-values, and confidence intervals using either command-line arguments or the set command.
Settings have also been added to control the display of factor variables in estimation tables. These display settings include extra space around factor variables, display of empty cells, display of base levels, and omitting variables that are excluded because of collinearity.
Stata/MP performance. Stata/MP, the parallel version of Stata, has several performance improvements, including even more parallelized panel-data estimators, improved parallelization of estimations with more than 200 covariates, and improved tuning of MP on large numbers of processors/cores.
Clipboard improvements. Clipboard support in the Data Editor has been enhanced. Copies to the Clipboard now retain variable formats and other characteristics of the data when pasted from within Stata.
Windows XP. The amount of memory available to Stata has been increased on 32-bit Windows XP.
Do-file Editor. Syntax highlighting, bookmarks, and other Do-file Editor features have been added to Stata for Mac.
ODBC. ODBC support has been added for Sun Solaris (Oracle Solaris).
Dialog boxes. Dialog boxes on Unix now have varlist controls that allow you to select variables from a list of variables in your dataset.
To learn more, type help whatsnew after updating to 11.1 and follow the links to the individual commands.
If you have not upgraded to Stata 11 yet, click here to see what’s new in Stata 11.