Difference in Difference Approach for Panel data

[Nadeem Sarwar]

hi
I performed a Lab experiment on 34 people (17 in control and 17 in treatment). I played 3 rounds and varied income tax rates to know how their performance varies with the change in tax rate. the control group had no option of tax evasion while treatment group had the option. pls, help me how to apply difference-in-difference approach on that.

thanks

[Carlo Lazzaro]

Nadeem:
see: http://www.princeton.edu/~otorres/DID101.pdf