HI, I basically want to estimate a Difference in Difference equation. IS there some application that help me to do it? 
If I want to it manually a just need to convert  panel data to cross section to estimate differences of my variables for pretreatment and treatment periods of time. However, I don't know how to do this either.
Thanks for your help.
Monica Ospina
Andrew Young School of Policy Studies
Georgia State University
Atlanta, GA  30302-3992
[email protected]
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