Before revision:  Unlike SCM, the proposed method does not rely on pre-intervention covariates , allows for nonconvex combinations of control units, can handle multiple treated units, and can share model parameters across time-steps.
After revision:  Unlike SCM, the proposed method does not rely on pre-intervention covariates to construct the synthetic control. RNNs do not assume a functional form, can learn nonconvex combinations of control units, can handle multiple treated units, and can share model parameters across time-steps.