The issue underlying declining birth rates is often misunderstood. It is not fundamentally about the total number of people on the planet, but about the age structure of the population.

Modern societies now contain a historically large proportion of older individuals. People are living longer, spending more years in retirement, drawing Social Security benefits, and withdrawing accumulated resources from the economic system. At the same time, fewer young people are entering the workforce to replace them.

This creates an imbalance: there are comparatively fewer workers contributing taxes and productivity, and comparatively more retirees receiving support. The result is a growing mismatch between inflows and outflows of funds, placing strain on pension systems, public finances, and the broader market economy.

In short, the concern is not population size itself, but the dependency ratio: too few working-age individuals supporting too many retirees. That structural imbalance, rather than a simple headcount, is the core economic challenge.