Impact evaluations are expensive and it is neither required nor possible to undertake impact evaluations of all programmes or policies. The use of impact evaluation has, however, garnered substantially greater attention in the field of development economics, health and education (Sabet and Brown, 2018), and is being used to inform and adjust policy-making in these fields (World Bank, 2009). Moreover while the costs of an impact evaluation can be high, designing or adjusting programmes without information on whether or not they work can be significantly more costly.