Development economics investigates the causes of poverty and low income around the world and seeks to make progress in designing policies that could help individuals, regions, and countries to achieve greater economic prosperity. (Acemoglu 2010:17)

In 1966, Ethiopia, India, and Thailand were all poor countries, [in which] a majority of people were living on less than $1 a day (in 1985 prices).…India did well, doubling per capita income between 1966 and 1990, and reducing poverty to 53 percent of the population.…Thailand did very well, tripling per capita income and cutting poverty to just 2 percent.…In 1966 Thailand had about four times Ethiopia's per capita income. By 1990 Ethiopians had seen no income growth, and Thailand was more than 10 times wealthier.…This difference is what Robert Lucas means by the “staggering consequences for human welfare” of different rates of growth and development. (World Bank 1998:29)