Statalist


[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

st: Maximization never converges


From   "Pavlos C. Symeou" <[email protected]>
To   [email protected]
Subject   st: Maximization never converges
Date   Sun, 14 Oct 2007 11:03:13 +0100

Dear Statalisters,

I am running a maximisation procedure based on Wang (2002, 2003) programme for the estimation of stochastic frontier models. The programme can estimate cross-sectional models and panel data models if, according to the author, one also includes firm-specific and time-specific dummies. Using my dataset, consisting of 144 countries and 15 years, the log-likelihood after a number of iterations (say 50) takes a value which does not change over subsequent iterations (after more than 1500 iterations with no change I had to break the procedure). In addition, STATA 10 SE never finds a concave estimate Every single iteration is not concave. Do you have a way to overcome this problem? I have also used the -difficult- option but this has been unsuccessful. The command is -ml max, diff gtol(0.001) gradient-

Yours,

Pavlos


"A Stochastic Frontier Analysis of Financing Constraints on Investment: The Case of Financial Liberalization in Taiwan ," Journal of Business and Economic Statistics, 2003, 21(3), pp.406-419.

"Heteroscedasticity and Non-Monotonic Efficiency Effects of a Stochastic Frontier Model," Journal of Productivity Analysis, 2002, 18, pp.241-253
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/




© Copyright 1996–2024 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index