Sub-replacement fertility compounds geometrically toward population collapse.

Evidence

The reason reproductive success is a powerful influence on group survival is that fertility rates decline geometrically—that is, the decline speeds up over time unless something gives. In an article titled “End of History and the Last Woman,” a team of researchers at The Economist did some calculations to forecast population declines happening in a great number of secular countries. In Hong Kong, for example, 1,000 women are expected to produce just 547 daughters; these, in turn, are expected to be succeeded by 299 daughters, and so on. Unless something changed, it would take just 25 generations for Hong Kong’s 3.75 million inhabitants to be reduced to just one person. — Norenzayan, Ara, Big gods - how religion transformed…, 498

Categorization

• CANDY: Hong Kong shrinking to one person in 25 generations is a striking, quotable number.
• XREF: Geometric decline argument aligns with the mathematical survival logic the reader deploys for religious group persistence.
• corroborated: 2 independent passages support this claim — Norenzayan, Ara, Big gods - how religion transformed…, 498