UNICEF Education has reviewed and is broadly supportive of Psacharopoulos, who backs their view that specific targets are needed for learning outcomes. They are keen to replace broad targets on universal education by realistic, measurable percentage increases in the numbers of children at school. UNICEF also note that there is a trade-off between economic efficiency and equity in some cases (for example, in the education of disabled children). It is suggested that cost-benefit analysis should therefore not be the sole factor used for decision-making. Their other substantive criticism is that Net Enrolment Ratio should be replaced by Primary Completion Rate as one of the key metrics used.