Economics of overpopulation

Many years ago, at a presentation about human overpopulation, the speaker mentioned that a big unanswered question in the field was why did the human population which had increased very slowly for the entirety of humanity suddenly start to grow at ever increasing rates. There was no observable correlation to social/cultural/technological/medical advances. While I can't recall the time/years being referenced, it was definitely between the first and second millennium.

Ever since that presentation, that puzzle would tickle my fancy whenever I came across an interesting historical fact. And now I am curious how human population correlates with economic advances - economic advances in the broad sense of any major innovation that substantively improved surplus production. By this definition, economic advances includes development of farming, domestication of animals for labor and food, currency, wage labor, and so on up to modern technology.

The advent of wage labor transformed people into economic units of production which means larger families had an economic advantage over small families. Was the increase in rate of population growth related to this form of economic pressure?

In today's economy, with the advent of robotic production, people have become units of consumption. But without jobs and the means to earn an income, people have no products or services to exchange for their consumption... does this exert pressure to decrease family size? This is an conundrum that 'business leaders', economists and politicians have yet to respond to.



Update: finally found the graph I wanted to include (original)


Makes me wonder about the influence of institutionized religion on world population growth.