Fertility data as policy early‑warning

Treat the UN/World Bank total fertility rate series as an operational early‑warning metric: rapid, sustained declines (or reversals) should automatically trigger cross‑sector policy reviews (education capacity, pension stress tests, housing demand forecasts, and labour‑market planning). Embed the series into fiscal and infrastructure modelling so demographic change feeds routine budget and permitting decisions rather than ad‑hoc political reactions. — Making fertility time series a formal signal would force governments to align budgets, urban planning, and social programs with demographic realities, preventing reactive scramble and misallocated resources.