There are bad leaders, good leaders, and great leaders. Let's start with one very bad one.
When I met Sani Abacha in 1997, the Nigerian dictator struck me as uninterested in matters economic, his eyes glazing over as I sketched Nigeria's untapped opportunities. But I later realized how badly I had misjudged him: In his short five years in office, he reportedly succeeded in amassing some $4 billion in private bank accounts overseas. It was only his country's economy that bored him. Good thing for Nigeria that he passed away when he did, in 1998. During the subsequent oil boom, more scrupulous leaders enabled Nigeria to accumulate $70 billion in reserves. Just think how much of that Abacha would have squirreled away.
Leaders matter, for better or, more likely, for worse. Sure, some of Asia's "benign" autocrats have turned their ambitions to building strong national economies. But not in Africa and many of the other countries that I call the bottom billion -- quite a number of which crowd the upper reaches of the Failed States Index. There, the most common form of autocracy is anything but benign. These leaders not only neglect to build the economy, they actively avoid doing so. The best-known instance is President Mobutu Sese Seko's order to "build no roads" in the vast country then known as Zaire. Why? Because without roads, it was harder for opponents to organize a rebellion against him.
The world, unfortunately, has many Mobutus. When I asked Kenya's autocratic president, Daniel arap Moi, why he had banned food imports from neighboring Uganda, his answer so tortured common sense that one of his aides had to take me aside and tell me the real story: Some of the president's businessman friends had stocks of food warehoused and wanted prices to rise. In Angola, I once asked a finance minister why, in defiance of economic logic, his country operated multiple exchange rates. The president used the dual system to siphon off money, he whispered. Until last year, Zimbabwe's Robert Mugabe did the same.
Bad guys matter, and when they rule, they make weak states weaker. And the countless anecdotes are backed up by numbers: In a celebrated study, economists Benjamin Jones and Benjamin Olken looked at whether the death of a country's leader altered economic growth. It did, sometimes for better and sometimes for worse. Recently, an Oxford colleague, Anke Hoeffler, and I sifted through their results again, distinguishing this time between democrats and autocrats. We found that in democracies, changing the leader does not change growth -- all leaders are disciplined to perform tolerably. But in autocracies, the growth rates are as unpredictably varied as the leaders' personalities. Here lies the difference between good leaders and great ones: Good leaders put right the policy catastrophes of bad leaders; great leaders, like the men who shaped the U.S. Constitution, build the democratic checks and balances that make good leaders redundant.
So much for the good and the great -- now back to the bad. Like Tolstoy's unhappy families, leaders can be bad in many different ways, and the extremes of their badness matter out of all proportion to their frequency in the population. At the extreme of greed are kleptocrats. At the extreme of insensitivity to the pain of others are psychopaths. At the extreme of preference for getting their own way are tyrants. Although people with such characteristics are rare, they have a knack for getting themselves into precisely those positions where their traits are most damaging. Kleptocrats do not aspire to become monks; they want to be bankers. Psychopaths do not dream of being nurses; they strive to be soldiers. Tyrants do not plead to be social workers; they scheme to become politicians.
At the core of all successful societies are procedures for blocking the advancement of such men. The safety mechanisms are often rather mundane. Britain, for example, transformed the 19th-century civil service from corruption to efficiency by replacing promotion by patronage with competitive examinations.
The weakest states utterly lack such defenses. There, as extremely bad people of all three varieties infiltrate a wide range of key positions, countries are brought to their knees -- and not just by politicians. Banks are routinely run by thieves who bankrupt them by "lending" the deposits to themselves. Rebel armies are led not by liberators, but by people more suited for a mental hospital. Take Liberian commander Prince Johnson, who filmed himself calmly sipping a beer while his captive, President Samuel Doe, was tortured to death.
But among the many varieties of badness, political tyranny is surely the most destructive. Politically ambitious crooks do not just fritter away the money they make from corruption; they invest it in future power. And that should frighten us most of all.
NEXT: The Worst of the Worst