Hi everyone,

I want to examine the effect of a treatment on an observation group with a Diff-in-Diff approach in a panel data setting in Stata. To avoid differences across subsamples I additionally using entropy balancing. Now, I have a methodical question.

I have already read some papers on this setting and noticed that the calculated weights of the pre-period are also used for the post-period. Why they not use the exact calculated weights in this case? I think in some ways this is data manipulation and I don't understand the theoretical explanation.

Here is an example of a paper in which Entropy Balancing is applied with panel data: http://dx.doi.org/10.2139/ssrn.3403486

Can anyone help me? Thank you very much!

I want to examine the effect of a treatment on an observation group with a Diff-in-Diff approach in a panel data setting in Stata. To avoid differences across subsamples I additionally using entropy balancing. Now, I have a methodical question.

I have already read some papers on this setting and noticed that the calculated weights of the pre-period are also used for the post-period. Why they not use the exact calculated weights in this case? I think in some ways this is data manipulation and I don't understand the theoretical explanation.

Here is an example of a paper in which Entropy Balancing is applied with panel data: http://dx.doi.org/10.2139/ssrn.3403486

Can anyone help me? Thank you very much!

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