5 The consequences of rapid population growth This chapter shows that rapid population growthat rates above 2 percent, common in most developing countries todayacts as a brake on development. Up to a point, population growth can be accommodated: in the past three decades many countries have managed to raise average Where the population is closed, meaning no migration, the population growth rate is the same as the rate of natural increase, i.e., the difference between the number of births and the number of deaths during a specified period of time. Over the past 100 years, the average growth rate of US real GDP per person is--. Growth rate was most rapid during the -- and the slowest during--. Between 1910 and 2010, the average growth rate of real GDP per person in the US was 2% a year. During this period,-- grew at a faster rate than--.