I spent some time a year ago or so reading Limits To Growth and Thinking In Systems by Donella Meadows - according to those theories, 8-9 billion is too high an

I spent some time a year ago or so reading Limits To Growth and Thinking In Systems by Donella Meadows - according to those theories, 8-9 billion is too high anyway. Their best case scenario is less than that, with everyone eventually settling into a standard of living that is about analogous to eastern European countries today (which is lower than the standard of living in the US).