Abstract: Comparative case studies is a research methodology to study the effect of events or policies on aggregate units such as regions or countries. The goal of these studies is to compare the evolution of an outcome for a single unit (a region or a country) affected by an event or policy with the evolution of a control group. However, it is often the case that there is not a single control unit with similar characteristics to the unit exposed and therefore a combination of control units is a better comparison group than any single unit. The synthetic control method specifies how to construct such a combination of control units, and carry out the comparison with the unit exposed. In this talk, I will review the synthetic control method and present various applications.