THE FUTURE BELONGS TO THOSE WHO SHOW UP: China will lose half its population by the end of the century — and the ripple effects will be catastrophic.

This year India is set to surpass China’s population, and in a few years it will surpass China’s working-age population — people 20 to 69. The United Nations has estimated that if China’s birth rate remains at its super-low level and the country fails to position itself as an attractive destination for migrants, the country will lose nearly half of its population by the end of this century, a contraction of roughly 700 million people.

Strong growth in its working-age population over the past several decades allowed China to become the world’s factory — over 70% of solar panels, 60% of farm machines, and 25% of robots are constructed with components from Chinese suppliers. Because of its manufacturing prowess and importance to supply chains, China’s shrinking working-age population has enormous, direct effects on the global economy. It’s also an omen for the US and Europe: If they don’t turn around their shrinking birth rates, they face the same economic fate as China.

But: “The large population decline is projected even though it assumes that China’s total fertility rate will rise from 1.18 children per woman in 2022 to 1.48 in 2100.”

Without that rise in fertility — which seems unlikely — China’s population will shrink even faster.