The primary sector tends to make up a larger portion of the economy in developing countries than it does in developed countries. For example, in 2018, agriculture, forestry, and fishing comprised more than 15% of GDP in Sub-Saharan Africa but less than 1% of GDP in North America.
In developed countries the primary sector has become more technologically advanced, enabling for example the mechanization of farming, as compared with hand-picking and -planting in poorer countries. More developed economies may invest additional capital in primary means of production: for example, in the United States corn belt, combine harvesters pick the corn, and sprayers spray large amounts of insecticides, herbicides and fungicides, producing a higher yield than is possible using less capital-intensive techniques. These technological advances and investment allow the primary sector to employ a smaller workforce, so developed countries tend to have a smaller percentage of their workforce involved in primary activities, instead having a higher percentage involved in the secondary and tertiary sectors.