The production-possibility frontier is strictly concave and negatively sloped if two commodities are produced according to linearly homogeneous, strictly quasi-concave production functions that use, with different intensities, two factors of production that are available in fixed supply. In this...

In 2006 the Center for Global Development's report 'When Will We Ever Learn? Improving lives through impact evaluation' bemoaned the lack of rigorous impact evaluations. The authors of the present paper researched international organizations and countries including Mexico, Colombia, South...