Before revision:  As our main contribution, we introduce\le  synthetic interventions (SI), which helps resolve this open problem by allowing one to produce counterfactual estimates if there are multiple interventions of interest .
After revision:  As our main contribution, we introduce\le T_0 < T, prior to which all units experience no intervention, i.e., control. We present a causal framework, synthetic interventions (SI), which helps resolve this open problem by allowing one to produce counterfactual estimates if there are multiple interventions of interest .