Do rich countries owe their wealth to institutions, geography or culture?

Economists offer three main kinds of answer, and the dispute is not settled. What is striking is how much the camps borrow from one another.

The institutions camp, led by Daron Acemoglu and James Robinson, argues that geography, climate, culture, religion, race and leaders' ignorance are insufficient explanations. Their evidence includes the "reversal of fortune": once-poor countries such as the US, Australia and Canada became rich despite poor natural endowments.

The geography camp replies. Jared Diamond insists geographical factors dominate; he points to tropical diseases in Zambia that keep male workers sick much of their lives. Jeffrey Sachs says the institutions book focuses too narrowly on domestic politics and ignores technology and geopolitics. He also says geography shapes institutions: West Africa's weak governments may reflect its unnavigable rivers. And Singapore and South Korea, he argues, easily refute the claim that democracy is a prerequisite for growth.

The third camp stresses culture. David Landes credited culture and enterprise, reviving, at least in part, Max Weber's idea that Protestant values pushed people to work hard and be punctual. Newer work suggests culture itself has roots: people whose ancestors were heavily raided in the slave trade are less trusting today, and agro-climatic conditions affect behaviour through culture.

The rivals even concede ground. Acemoglu and Robinson agree geography is crucial in shaping institutions, though not deterministically. Francis Fukuyama, who calls the inclusive/extractive split an oversimplification, still writes that the modern state and the rule of law help growth.