The focus on results in development agencies has led to increased focus on impact evaluation to demonstrate the effectiveness of development programmes. This book illustrates the broad range of methods available for counterfactual analysis of infrastructure programmes such as establishment, rehabilitation and maintenance of roads, water supply and electrical power plants and grids. Understanding the impact of interventions requires understanding of the context in which the intervention takes place and the channels through which it is expected to occur. For infrastructure interventions it is particularly important to identify the links between the input and the outcomes and impacts because the well-being of people, the ultimate impact, does not change directly as a consequence of the intervention. Therefore impact evaluation of infrastructure programmes typically requires mixing both quantitative and qualitative approaches as illustrated in many of the contribution to this edited volume. This book was originally published as a special issue of the Journal of Development Effectiveness.