Birth rate
The region of Sub-Saharan Africa has the highest birth rate in the world. As of 2016, Niger, Mali, Uganda, Zambia, and Burundi have the highest birth rates in the world. This is part of the fertility-income paradox, as these countries are very poor, and it may seem counter-intuitive for families there to have so many children. The inverse relationship between income and fertility has been termed a "demographic-economic "paradox"" by the notion that greater means would enable the production of more offspring as suggested by the influential Thomas Malthus.
Woman
The total fertility rate (TFR) – the average number of children born to a woman over her lifetime — differs significantly between different regions of the world. In 2016, the highest estimated TFR was in Niger (6.62 children born per woman) and the lowest in Singapore (0.82 children/woman). While most Sub-Saharan African countries have a high TFR, which creates problems due to lack of resources and contributes to overpopulation, most Western countries currently experience a sub replacement fertility rate which may lead to population ageing and population decline.