Why Nations Fail
Daron Acemoglu & James A. Robinson · 2012
"Nations grow rich or stay poor mainly because of their political and economic institutions — whether they're 'inclusive' (broadly distributing power and property rights) or 'extractive' (concentrating both in a narrow elite) — not because of geography, culture, or the knowledge available to their leaders."
Acemoglu and Robinson studied cities split by the same border — like Nogales, split between Arizona and Mexico, same geography and culture on both sides — and found wealth gaps that geography and culture couldn't explain. Institutions could.
Read more about the topic
Guns, Germs, and Steel
"Which civilizations ended up conquering others was driven overwhelmingly by geographic and environmental accident — access to domesticable plants and animals, and an east-west continental axis that let farming spread easily — not by any difference in the people themselves."