Does anyone govern well in Africa?

The Mo Ibrahim Foundation's announcement this week that it could not find anyone worthy of its £3m African leadership prize appears a damning verdict on the state of governance on the continent.

Admittedly, the prize's criteria are rather specific, aimed at leaders who have relinquished power, but not too long ago. Candidates must be "former executive heads of state or government . . . who have taken office through democratic elections and left office in the previous three years, having served the constitutional term as stipulated when taking office."

Optimists believe that multi-party democracy is steadily but inexorably spreading in Africa, but it is often a case of two steps forward, one step back. Guinea, Mauritania and Madagascar have recently witnessed coups, while Chad, Cameroon and Uganda have amended their constitutions so their leaders can cling on to power. Even democracies can look like one-party states. Botswana went to the polls last week and re-elected a party that has ruled for 43 years.

Meanwhile, Kenya, Madagascar and Zimbabwe have brought rivals together in unity governments which might avert immediate crisis but can appear self-serving and accountable to no one.

So what might the Ibrahim prize committee's shortlist have looked like, and why didn't they make the grade?

▶ John Kufuor, Ghana

Won praise for making Ghana an example of stability in the continent; attracted Barack Obama on his first presidential visit to Africa. But opponents accused his government of corruption. Enjoys a hugely lucrative retirement package.

▶ Thabo Mbeki, South Africa

Presided over economic growth, but was forced out of office last year after a fierce power struggle. His denialist attitude to Aids was blamed for the deaths of 300,000 people, and his failure to condemn Zimbabwe's Robert Mugabe drew further criticism.

▶ Olusegun Obasanjo, Nigeria

A canny politician adept at being in the right place at the right time. But his presidency was marred by corruption, human rights abuses and huge poverty despite the nation's oil wealth.