CAMBRIDGE ― On Oct. 14, the Mo Ibrahim Prize Committee announced that for the second year in a row it had not found anyone to whom to award its Prize for Achievement in African Leadership. Why is that important?

The prize is given to a recently retired African head of state or government who was democratically elected, stepped down at the end of his or her constitutionally mandated term, and demonstrated exceptional leadership. The winner receives $5 million paid over 10 years, followed by $200,000 annually for life, making it the world’s most valuable annual award.

The Mo Ibrahim Foundation supports other important activities, particularly the annual Ibrahim Index of African Governance, which was also released on Oct. 14. But I am especially intrigued by the prize. It is a fascinating social-policy experiment, which deserves to be more widely known.

Critics of the Ibrahim Prize argue that it makes Africa look bad, because in four out of seven years it has not been awarded to anyone. It has also been argued that leaders should not have to be “bribed” into being good. The good will be good, and the bad will be bad, regardless of the prize.

I don’t buy these criticisms. Yes, other parts of the world also suffer from governance problems. And more people should be aware that many African countries have made substantial progress over the last decade, particularly with respect to economic growth, health, and education. But those are not arguments against highlighting the important role of leadership in African countries’ success.

Given the abundant attention received by Africa’s truly awful leaders, it is useful to focus on its good ones. And the money that comes with the Ibrahim Prize is enough that it could affect leaders’ behavior.

The Ibrahim Prize was awarded in 2007, 2008, and 2011 to Presidents Joaquim Chissano of Mozambique, Festus Mogae of Botswana, and Pedro Verona Pires of Cape Verde, respectively. Botswana and Cape Verde are two of the small-population countries that are consistently placed near the top in rankings of African governance, human development, and economic performance.

Mozambique is different: larger and historically in much worse shape, it suffered a terrible civil war from 1977 to 1992. Even after two decades of strong political and economic improvement, it still ranks low on most development indicators.

What defines good leadership is a notoriously complicated question. Should leadership be evaluated according to criteria like economic prosperity, public health, respect for human rights, personal security, and peace? Or are the proper criteria the leader’s character and competence, including his or her ability to inspire the country, choose good officials, formulate good policies, and implement them? In a word, is leadership a matter of outcomes or inputs?

Successful outcomes are obviously the ultimate objective. But it is not useful to rely solely or primarily on outcomes to judge a leader. Many factors beyond a leader’s control can block his or her country’s progress. Even if good leadership means a demonstrated ability to prevail in the face of intransigent domestic political opposition, coup attempts, and invasions, surely no leader can be held responsible for the effects of droughts, floods, or other natural disasters.

Admittedly, a leader’s integrity and competence are more difficult to measure than outcomes (such as per capita income, life expectancy, infant mortality, literacy, and crime). But some of the component indicators of the IIAG (such as rule of law, bureaucratic red tape, and fiscal policy) are more directly under government control.

In any case, one would not expect prize committees or historians to judge leaders solely by quantitative criteria. Few Americans thought Harry Truman had been a good president immediately after he left office, but now he is rated very high. In Mexico, Carlos Salinas looked good at the time, but is now viewed poorly, while the accomplishments of his successor, Ernesto Zedillo, now appear bold, historic, innovative, and valuable.

The list of eligible candidates for the Ibrahim Prize begins with those who were democratically elected and left office constitutionally within the preceding three years. In a typical year, there may be as few as three candidates who meet these qualifications. The question is then whether any candidate demonstrated the necessary level of excellence in office. In 2009, 2010, 2012, and now 2013, the prize committee decided that none had.

Does that mean that the prize has failed to meet the objective of encouraging good leadership in Africa?

Consider a ruler who comes to power with good intentions and great abilities. Assume that he accomplishes much for his country during his first term (or his first two or three terms if the constitution allows it). But he stays too long (Uganda’s Yoweri Museveni comes to mind). He forces through constitutional changes so that he can run for more terms. Then he starts rigging elections and suppressing opposition. He or members of his family nurture large overseas bank accounts.

Such leaders’ personalities may have changed. They may now regard themselves as indispensable. They have been corrupted by power, like the porcine elite in George Orwell’s Animal Farm. At this point, they are unlikely to be influenced by the money that comes with the Ibrahim Prize.

But now consider a leader who would prefer to serve honestly throughout his term and depart voluntarily. This path might leave a retirement with few resources for him and his family, little in the way of prestige or a platform from which to speak, and perhaps persecution by his successors. It is precisely such a leader for whom the Ibrahim Prize could make the difference, influencing him to continue on the high road.

If the experiment works, however, the main fruits will lie in the future. The Ibrahim Prize was established only in 2007, which means that the candidates have served most of their terms in office at a time when the prize could not have influenced their behavior. If it does have the desired effect, we should start seeing winners in more years.

By Jeffrey Frankel 

Jeffrey Frankel is professor of capital formation and growth at Harvard University. ― Ed.

(Project Syndicate)