As of December 2015, the world's poorest countries are the Central African Republic, the Democratic Republic of Congo, Malawi, Liberia and Burundi. Each of these countries is in sub-Saharan Africa. In fact, the 13 poorest countries in the world all are in this region.
The wealth rankings listed here are based on each country's gross domestic product and its purchasing power parity ranking, which offers a comparison of the cost of living and standard of living across countries.
The sub-Saharan region has long been home to the world's poorest nations, mostly on account of its long-term political instability, poor agricultural conditions and geographic considerations, such as its harsh climate and land-locked geography.
These countries often deal with poor soil; a lack of natural resources, such as a scarcity of water, both for everyday living and as a means of transport; and common plagues of insects, such as tsetse flies and mosquitoes, both of which spread disease. Further, the populations of the countries are poorly educated, and most people live only at or below the subsistence level. Their circumstances make it very challenging to grow businesses or farms and to generate capital, all of which are needed to improve the wealth of the countries.