I studied biology in college and this has always been obvious to me, and it shocks me that people with backgrounds in e.g. ecology don't understand that living systems are unpredictable auto-adaptive machines full of feedback loops. How a bunch of ecologists could take doomerism based on "world models" seriously enough to cause a public panic about it (e.g. Paul Ehrlich) baffles me.

Human cultural systems are even worse than non-human living systems: they actively fight you. They are adversarial with regard to predictions made within them. If you're considered a credible source on economics and you say a recession is coming, you change the odds of a recession by causing the system to price in your pronouncement. This is part of why market contrarianism kind of works, but only if the contrarians are actually the minority! If contrarianism becomes popular, it stops being contrarian and stops working.

So... predicting doom and gloom from overpopulation would obviously reduce the future population if people take it seriously.

Tangentially, everything in economics is a paradox. A classic example is the paradox of thrift: if everyone is saving nobody can save because for one to save another must spend. Pricing paradoxes are another example. When you're selling your labor as an employee you want high wages, high benefits, jobs security, etc, but when you go shopping you want low wages, low benefits, and a fluid job market... at least if you shop by comparing on price. If you are both a buyer and a seller of labor you are your own adversary in a two-party pricing game.

I personally hold the view that the arrow of time goes in one direction and the future of non-linear computationally irreducible systems cannot be predicted from their current state (unless you are literally God and have access to the full quantum-level state of the whole system and infinite computational power). I don't mean predicting them is hard, but that it's "impossible like perpetual motion" impossible.

I also wonder if we are being fooled by randomness when we think we see a person or a technique that yields good predictions. Are good prophets just luck plus survivorship bias? Obviously we forget all the bad prophets. All lottery winners are lucky, therefore lucky people should play the lottery. But who is lucky? The only way to find out is to play the lottery. Anyone who wins should have played, and anyone who loses should not have played.