Development economics is a branch of macroeconomics that deals with the study of the causes of long term economic growth, especially in developing countries. This may involve using mathematical methods from dynamical systems like differential equations and inter-temporal optimization, or it may involve a mixture of quantitative and qualitative methods.

Development economics also includes topics such as Third World debt, and the functions of such organisations as the IMF and World Bank. Many economists in this field are interested in ways of promoting stable and sustainable growth in poor countries and areas, by promoting self reliance and education in some of the lowest income countries in the world. Where economic issues merge with social and political ones, it is referred to as Development Studies.

More recent theories of Human Development have began to see beyond purely economic measures of development, for example with measures such as the Genuine Progress Indicator, and relate strongly to theories of distributive justice.

The most prominent contemporary development economist is perhaps the Nobel laureate Amartya Sen.