Interesting article -- especially the part about how the guy was actually optimistic about the future of humanity. He saw his work as a way to study how humans could overcome the issues he uncovered. Instead it was seen as a dystopian warning.

Personally I think overpopulation is a self-limiting problem, and not necessarily in the ways suggested by the rat colonies. When people have plenty of resources and are more educated, they tend to have fewer children. Large families are a hedge against death through misadventure and disease, and they provide cheap labor in a labor-intensive society.