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synth-inference / synthdid

Synthetic difference in differences
https://synth-inference.github.io/synthdid
BSD 3-Clause "New" or "Revised" License
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Question about weights #96

Open TXU0429 opened 1 year ago

TXU0429 commented 1 year ago

Hi,

I tried the california_prop99 example and it worked as in the paper. However, I am a little confused about the weights. In the results, synthdid returned controls weights and periods weights but not for all control units and not for all time periods. I wonder what are the weights for other control units and time periods. Just keep them as how they are originally in the dataset?

For example, for periods weights, I got > print(summary(tau.hat)$periods) estimate 1 1988 0.427 1986 0.366 1987 0.206

So for other years before treatment (1970 - 1985), the weights are 1?

Thank you!

davidahirshberg commented 1 year ago

They’re zero. The weights you’re reporting sum to one.