Increasingly both donor agencies and recipient governments want to assess the effectiveness of aid. Unfortunately, existing methods for impact evaluation are designed for the evaluation of homogeneous interventions ('projects') where those with and without 'treatment' can be compared. However,...

Donor agencies and recipient governments want to assess the effectiveness of aid-supported sector policies. Unfortunately, existing methods for impact evaluation are designed for the evaluation of homogeneous interventions (‘projects’) where those with and without ‘treatment’ can be...

There is a growing interest, notably in development economics, in extending project evaluation methods to the evaluation of multiple interventions (“programs”). In program evaluations one is interested in the aggregate impact of a program rather than the effect on individual beneficiaries....