You can chart the search for a theory of inequality to the French political philosopher Montesquieu, who in the mid-eighteenth century came up with a very simple explanation: People in hot places are inherently lazy. Other no less sweeping explanations soon followed: Could it be that Max Weber's Protestant work ethic is the true driver of economic success? Or perhaps the richest countries are those that were former British colonies? Or maybe it's as simple as tracing which nations have the largest populations of European descent? The problem with all of these theories is that while they superficially fit some specific cases, others radically disprove them. [...]And yet while Sachs and Diamond offer good insight into certain aspects of poverty, they share something in common with Montesquieu and others who followed: They ignore incentives. People need incentives to invest and prosper; they need to know that if they work hard, they can make money and actually keep that money. And the key to ensuring those incentives is sound institutions — the rule of law and security and a governing system that offers opportunities to achieve and innovate. That's what determines the haves from the have-nots — not geography or weather or technology or disease or ethnicity.
Put simply: Fix incentives and you will fix poverty. And if you wish to fix institutions, you have to fix governments.
Easier said than done, but true nonetheless.