Public Policy Evaluation: Randomized experiments and quasi-experimental methods.

Summary In this article, we provide an introduction to experimental and quasi-experimental evaluation methods. The objective of these methods is to econometrically identify the causal effects of public policies. We present the concepts and insights using simple numerical examples, supplemented by tables and graphs, without resorting to advanced econometric techniques. We illustrate the discussion with concrete examples, including for example the active solidarity income (RSA) policy, a dam construction project, a vocational training program, and agro-environmental measures. We systematically discuss the main biases and potential problems associated with each method.