Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
| From | Arne.Bueschemann@wiwi.uni-paderborn.de |
| To | statalist@hsphsun2.harvard.edu |
| Subject | st: stochastic frontier analysis efficiency scores |
| Date | Fri, 19 Feb 2010 11:39:35 +0100 |
We have a panel dataset covering all Valuations for 30 companies for each year between 2001 and 2009 as well as several independent variables. Therefore, we applied a xtfrontier model to discover the technical efficiency for each company and each year. Now we have the problem that the efficiency scores vary in each year but the yearly ranking of all companies remains the same which we consider highly unlikely. We used following command: xtfrontier logdep indep1 indep2 l indep3 l indep4 l indep5 l indep6 l indep7, tvd i(id) t( idtime) and for the post estimation we used: predict efficiency, te What we try to find out: Does the efficiency of the companies increase or decrease over time and does the ranking between the companies change in regard to technical efficiency. Therefore, we are not quite sure how to use xtfrontier command or if we should apply frontier analysis for each year separately. We would appreciate your help and to let us know which model we should apply Best regards, Arne * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/