To improve the likelihood of reaching the Millennium Development Goals (MDGs), or more generally to improve their social indicators, countries (or states and provinces within countries) basically have two options: increasing the inputs used to "produce" the outcomes measured by the MDGs, or increasing the efficiency with which they use their existing inputs. The four papers presented in this study look at whether improvements in efficiency could bring gains in outcomes. The first two papers use world panel data in order to analyze country level efficiency in improving education, health, and GDP indicators (GDP is related to the MDGs because a higher level of income leads to a reduction in poverty). The other two papers use province and state level data to analyze within-country efficiency in Argentina and Mexico for "producing" good education and health outcomes. Together, the four papers suggest that apart from increasing inputs, it will be necessary to improve efficiency in order to reach the MDGs. While this conclusion is hardly surprising, the analysis helps to quantify how much progress could be achieved through better efficiency, and to some extent, how efficiency itself could be improved.