Populations can adjust. When there are too many people, and food is expensive or hard to get, people make fewer kids, or invest in making it cheaper (agricultu

Populations can adjust. When there are too many people, and food is expensive or hard to get, people make fewer kids, or invest in making it cheaper (agriculture innovations - nearly 50% of the nitrogen found in human tissues originated from the Haber–Bosch process [1]). When there are too few people, and a lot of states rely on taxing youth to fund pensions and healthcare for elders, anyone able and willing to work will be paid better, attracting migrants or older workers. [1] - Last paragraph here: https://en.wikipedia.org/wiki/Haber_process#Economic_and_environmental_aspects https://en.wikipedia.org/wiki/Haber_process#Economic_and_env...