  Iterative Synthetic Control Method is introduced in this study, a
modification of the Synthetic Control Method (SCM) designed to improve its
predictive performance by utilizing control units affected by the treatment in
question. This method is then compared to other SCM modifications: SCM without
any modifications, SCM after removing all spillover-affected units, Inclusive
SCM, and the SP SCM model. For the comparison, Monte Carlo simulations are
utilized, generating artificial datasets with known counterfactuals and
comparing the predictive performance of the methods. Generally, the Inclusive
SCM performed best in all settings and is relatively simple to implement. The
Iterative SCM, introduced in this paper, was in close seconds, with a small
difference in performance and a simpler implementation.
