Immigrants are drawn from neighboring nations by economic opportunity. On 17 January 1983, Nigeria, suffering from an economic crisis brought about by decreased earnings from oil, ordered all resident aliens to leave the country. Some 700,000 Ghanaians departed during the following weeks, as did smaller numbers from Benin, Cameroon, Chad, Mali, Niger, Togo, and Burkina Faso. In 1985, about 200,000 to 250,000 aliens were expelled, including about 100,000 from Ghana and 50,000 from Niger.
As of 1999, there were some 6,000 refugees in Nigeria. Of these, some 2,660 were settled in a camp at Oru. The majority of refugees were from Sierra Leone (1,865), Chad (1,600), and Liberia (1,300). The remainder was made up of small groups from Congo, Sudan, and Ethiopia. In 2,000 the total number of migrants was 751,000, including 7,300 remaining refugees. The net migration rate in 2000 was -0.2 migrants per 1,000 population. Worker remittances in that year amounted to $1,301 million, or 5% of GDP. The government views the migration levels as satisfactory.