Elon Musk on demographics: what the evidence says · JRE #2281
“Yeah. At current birth rates, in three generations, Korea will be about 4% of its current size.”
What the evidence says
South Korea does have the world's lowest fertility rate, recorded at roughly 0.72-0.78 births per woman in recent years, well below the 2.1 replacement level, and its population has been declining since 2020. Musk's "4% of current size in three generations" figure appears to come from cubing a rough one-third-of-replacement ratio (roughly 1/27, about 3.7%), a simple compounding extrapolation rather than a demographic model. Mainstream population projections do not use this method and produce far less extreme outcomes: UN and other long-range projections for South Korea generally show substantial decline by 2100 but nowhere near a 96% reduction, since they account for fertility rates changing over time, migration, and mortality rather than holding today's birth rate constant and compounding it across generations. Demographers do treat South Korea's fertility collapse as a severe, arguably unprecedented crisis, so the underlying concern is well-founded, but Musk's specific numeric extrapolation is considerably more extreme than standard demographic projections.