Oportunidades is a Conditional Cash Transfer (CCT) that uses a proxy means-test targeting model to select eligible households for the programme. According to the Income and Expenditure Household Survey of 2008, approximately two in every three eligible rural households participate in Oportunidades, whereas only one in every three eligible urban households receives the Oportunidades cash transfer. This research explores the factors behind this lack of take-up, the costs of participation and the implications of targeting inefficiency on the programme’s impact on income poverty. It argues that a sample selection model is a pertinent tool of analysis as it informs on the distribution of cash transfers conditional on household eligibility. Thi...