Dear all:
We are applying a Difference in Differences (DiD) estimator to study the treatment effect of a healthcare program.
We would like to discuss our results in terms of the usual program evaluation effects like 'average treatment' or 'average treatment on the treated' etc.
To this end, we would like to show how the DiD estimator relates to ATE and/or ATT (and under what precise assumptions).
We are confused because here (http://en.wikipedia.org/wiki/Average_treatment_effect) it says essentially that DiD=ATE, whereas here (http://www.ucl.ac.uk/~uctp39a/Blunde...s-Dec-2007.pdf) on page 18 it says that DiD=ATT.
We would be grateful if anyone can help us with a reference where we can find precise conditions such as 'DiD=ATE if xy holds' and 'DiD=ATT if nn holds'.
(We already read the advanced Wooldridge text but did not get to the answer.)
Thanks for your help!
Marc
We are applying a Difference in Differences (DiD) estimator to study the treatment effect of a healthcare program.
We would like to discuss our results in terms of the usual program evaluation effects like 'average treatment' or 'average treatment on the treated' etc.
To this end, we would like to show how the DiD estimator relates to ATE and/or ATT (and under what precise assumptions).
We are confused because here (http://en.wikipedia.org/wiki/Average_treatment_effect) it says essentially that DiD=ATE, whereas here (http://www.ucl.ac.uk/~uctp39a/Blunde...s-Dec-2007.pdf) on page 18 it says that DiD=ATT.
We would be grateful if anyone can help us with a reference where we can find precise conditions such as 'DiD=ATE if xy holds' and 'DiD=ATT if nn holds'.
(We already read the advanced Wooldridge text but did not get to the answer.)
Thanks for your help!
Marc
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