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.
Macau
The growth of population in Macau mainly relies on immigrants from mainland China and the influx of overseas workers since its birth rate is one of the lowest in the world. According to "The World Factbook", Macau has the fourth highest life expectancy in the world, while its infant mortality rate ranks among the lowest in the world.