Impact Evaluation of Multiple Overlapping Programs using Difference-in-differences with Matching

Difference-in-differences with matching is a popular method in impact evaluation. Traditional impact evaluation methods including difference-in-differences with matching often deal with impact measurement of a single binary program. Imbens (1999) and Lechner (2001) extend the matching method to the case of multiple mutually exclusive programs. Frölich (2002) discusses different impact evaluation methods in the similar context. In reality, one can participate in several programs simultaneously and the programs may be overlapping. This paper discusses the method of difference-in-differences with matching in a general context of multiple overlapping programs. The method is applied to measure impacts of formal and informal credit in Vietnam using panel data from two Vietnam Household Living Standard Surveys in 2002 and 2004.