Niger is a landlocked country in Western Africa. Neighboring countries include Algeria, Benin, Burkina Faso, Chad, Libya, Mali, and Nigeria. The northern four-fifths of the country is desert, and the southern one-fifth is savanna. The government system is a semi-presidential republic; the chief of state is the president, and the head of government is the prime minister. Many of the citizens rely on subsistence farming, but Niger has a largely free-market system in which the prices are set by the market. Niger is a member of the Economic Community of West African States (ECOWAS).