I am interested in conducting causal inference using synthetic control method using R where there are multiple treated units/regions. The current synth package allows only one treated unit to be compared to other (several) synthetic units. In my case, I have 5 treated units and 35 untreated units. Is there any package I have missed? I am currently doing a sequential analysis comparing each treated unit to the 35 untreated units. I would like to get a composite result. Any help will be appreciated. Sincerely, Peter Maclean Department of Economics UDSM