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The UN Population Division have underestimated population growth for decades and base their projections on the assumption that fertility will converge on a stea
by barry-cotter 7y ago
The UN Population Division have underestimated population growth for decades and base their projections on the assumption that fertility will converge on a steady state. This is evolotuniariliy illiterate. People who have more children will have children who have more children.
https://www.sciencedirect.com/science/article/pii/S1090513817302799#bb0180 https://www.sciencedirect.com/science/article/pii/S109051381...
The heritability of fertility makes world population stabilization unlikely in the foreseeable future
The forecasting of the future growth of world population is of critical importance to anticipate and address a wide range of global challenges. The United Nations produces forecasts of fertility and world population every two years. As part of these forecasts, they model fertility levels in post-demographic transition countries as tending toward a long-term mean, leading to forecasts of flat or declining population in these countries. We substitute this assumption of constant long-term fertility with a dynamic model, theoretically founded in evolutionary biology, with heritable fertility. Rather than stabilizing around a long-term level for post-demographic transition countries, fertility tends to increase as children from larger families represent a larger share of the population and partly share their parents' trait of having more offspring. Our results suggest that world population will grow larger in the future than currently anticipated.