Editors
H. Joseph Newton
Department of Statistics
Texas A&M University
College Station, Texas
editors@stata-journal.com
Nicholas J. Cox
Department of Geography
Durham University
Durham, UK
editors@stata-journal.com
Associate Editors
Christopher F. Baum, Boston College
Nathaniel Beck, New York University
Rino Bellocco, Karolinska Institutet, Sweden, and
University of Milano-Bicocca, Italy
Maarten L. Buis, WZB, Germany
A. Colin Cameron, University of California–Davis
Mario A. Cleves, University of Arkansas for
Medical Sciences
William D. Dupont, Vanderbilt University
Philip Ender, University of California–Los Angeles
David Epstein, Columbia University
Allan Gregory, Queen’s University
James Hardin, University of South Carolina
Ben Jann, University of Bern, Switzerland
Stephen Jenkins, London School of Economics and
Political Science
Ulrich Kohler, WZB, Germany
Frauke Kreuter, Univ. of Maryland–College Park
Peter A. Lachenbruch, Oregon State University
Jens Lauritsen, Odense University Hospital
Stanley Lemeshow, Ohio State University
J. Scott Long, Indiana University
Roger Newson, Imperial College, London
Austin Nichols, Urban Institute, Washington DC
Marcello Pagano, Harvard School of Public Health
Sophia Rabe-Hesketh, Univ. of California–Berkeley
J. Patrick Royston, MRC Clinical Trials Unit,
London
Philip Ryan, University of Adelaide
Mark E. Schaffer, Heriot-Watt Univ., Edinburgh
Jeroen Weesie, Utrecht University
Nicholas J. G. Winter, University of Virginia
Jeffrey Wooldridge, Michigan State University
Stata Press Editorial Manager
Lisa Gilmore
Stata Press Copy Editors
David Culwell and Deirdre Skaggs
The Stata Journal publishes reviewed papers together with shorter notes or comments, regular columns, book
reviews, and other material of interest to Stata users. Examples of the types of papers include 1) expository
papers that link the use of Stata commands or programs to associated principles, such as those that will serve
as tutorials for users f i rst encountering a new f i eld of statistics or a major new technique; 2) papers that go
“beyond the Stata manual” in explaining key features or uses of Stata that are of interest to intermediate
or advanced users of Stata; 3) papers that discuss new commands or Stata programs of interest either to
a wide spectrum of users (e.g., in data management or graphics) or to some large segment of Stata users
(e.g., in survey statistics, survival analysis, panel analysis, or limited dependent variable modeling); 4) papers
analyzing the statistical properties of new or existing estimators and tests in Stata; 5) papers that could
be of interest or usefulness to researchers, especially in f i elds that are of practical importance but are not
often included in texts or other journals, such as the use of Stata in managing datasets, especially large
datasets, with advice from hard-won experience; and 6) papers of interest to those who teach, including Stata
with topics such as extended examples of techniques and interpretation of results, simulations of statistical
concepts, and overviews of subject areas.
The Stata Journal is indexed and abstracted by CompuMath Citation Index, Current Contents/Social and Behav-
ioral Sciences, RePEc: Research Papers in Economics, Science Citation Index Expanded (also known as SciSearch,
Scopus, and Social Sciences Citation Index.
For more information on the Stata Journal, including information for authors, see the webpage
http://www.stata-journal.com