Re: Programming an estimation command in Stata: Mata functions

-xtabond2- is a community-contributed command, and technical
support for these commands is provided by their author. The contact information can usually be found at the bottom of the help file. If you'd like, you can email our Technical Support team at tech-support@stata.com with a copy of your .dta file and the do-file that reproduces the error; they will be happy to take a look.