Timeline for A difference-in-differences propensity score matching approach
Current License: CC BY-SA 4.0
5 events
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| Mar 16, 2019 at 4:47 | comment | added | Noah |
Yes, entropy balancing guarantees exact balance on all the covariates you request balance on. The problems with it are that it will fail if the problem is infeasible (i.e., it's impossible to achieve exact balance) and in some cases, the effective sample size of the balanced samples is very small and your standard errors become huge. One solution is approximate balancing, such as by using the R package optweight (which I wrote), but there hasn't been much written about this method and none of it in the context of DID.
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| Mar 15, 2019 at 0:28 | comment | added | Nivas | Yes, you are correct. I am trying to see if my control group satisfies the parallel trend of treatment group for pre-intervention so that I can use DID in post . Thanks for your suggestion Noah , I will try to use Entropy balancing . So do you think, Entropy balancing can be used to find better control group which will most likely satisfy/match with treatment group in pre-intervention time periods. | |
| Mar 14, 2019 at 23:24 | comment | added | Noah | Are you assessing the parallel trends assumption by using several pre-intervention time periods and seeing that the pre-intervention trends are not parallel? If so, then your matching has failed and you should try another method of matching or otherwise equating the groups to ensure the pre-intervention trends looks the same. Entropy balancing is a good and simple way to do this. | |
| Mar 14, 2019 at 20:26 | comment | added | Nivas | Thanks for your comment Noah. The post treatment in DID is all about comparing the changes in outcomes over time between a population that is enrolled in a program (the intervention group) and a population that is not (the control group). And if the control group which I found using propensity score doesn't follow parallel trend or if it's not even close enough to test, then how can i do the post. mailman.columbia.edu/research/population-health-methods/…. | |
| Mar 14, 2019 at 0:30 | history | answered | Noah | CC BY-SA 4.0 |