Short answer: no, but it is extremely unpredictable (hence the billions of people between the low and high forecasts). You can look at countries as incomes incr

Short answer: no, but it is extremely unpredictable (hence the billions of people between the low and high forecasts). You can look at countries as incomes increase, infant mortality decreases etc, and see patterns in fertility. And fertility rates do sometimes increase or decrease for poorly understood reasons, but they're not random: https://www.google.com/publicdata/explore?ds=d5bncppjof8f9_&met_y=sp_dyn_tfrt_in&idim=country:USA:CHN:JPN&hl=en&dl=en https://www.google.com/publicdata/explore?ds=d5bncppjof8f9_&....