Answer: World Bank
Notes: The World Bank's latest World Development Report focuses on the middle-income (MI) trap, highlighting that it may take nearly 75 years for economies currently in this trap to progress. Since 1987, the World Bank has classified economies into four categories: high income, upper middle income, lower middle income, and low income. While high-income countries have doubled from 41 to 86, low-income countries have reduced from 49 to 26. Currently, there are 108 middle-income countries, making up 75% of the global population and contributing about 38% of global GDP.
