JOHANNESBURG // The great democratic and economic strides made by African countries in the past decade risk being checked by ageing leaders unwilling to pass the baton.
For generations of foreign investors accustomed to the likes of Uganda's Idi Amin and the former Zaire's Mobutu Sese Seko, it took a while to shake off the stereotype of African leaders as psychotic kleptocrats hellbent on retaining power.
And not without justification. From 1960 to 2010, during 653 elections on the continent, the incumbent conceded defeat just 16 per cent of the time, according to an African Development Bank study.
But as better governance has swept from Senegal to Lesotho, the world's perceptions have slowly caught up.
Investors who once fearfully dipped their toes in African waters, have seen that the old crocodiles are dead or dying and have begun to wade in.
Progress has not been universal, but in much of Africa, "Number One" is as likely to be a former World Bank economist as an army general.
So last week when Robert Mugabe, 89, was sworn in as Zimbabwe's president for another five years, it was something of a blast from the past.
"I still have ideas, ideas that need to be accepted by my people," Mr Mugabe, who has ruled Zimbabwe since independence in 1980, told The New York Times on the eve of the vote.
If the election results are accurate, Mr Mugabe's anti-colonial message won him 61 per cent support in a country where 60 per cent of the population have never experienced colonialism.
But Mr Mugabe is far-from the only independence-era leader still kicking about in the presidential palace.
The average age of leaders on the African continent is around 60 years old, yet half of the population is under the age of 19.
"What's wrong with us?" Sudanese-born billionaire Mo Ibrahim recently asked, wondering whether Barack Obama could have become president of Kenya aged 47.
Probably not, concluded Mr Ibrahim, who in 2006 created a foundation that awards prizes for achievement in African leadership and monitors good governance on the continent.
In Angola, Jose Eduardo dos Santos has been in power for fractionally longer than Mugabe's 33 years. He won another five-year term last year.
The Angolan economy is growing at a clip, but corruption is rife and while the rich have done well, wealth has not spread very far from Mr dos Santos's inner circle.
His daughter Isabel dos Santos is rumoured to be worth around $3 billion (2.4 billion euros).
Aside from Mr Mugabe and Mr dos Santos, there is a long list of African leaders old enough to draw their pensions.
They include Ethiopia's Girma Wolde-Giorgis, 88, Cameroon's Paul Biya, 80, Zambia's Michael Sata, 76, Equatorial Guinea's Teodoro Obiang, 71, and Uganda's Yoweri Museveni, 69.
Having old leaders is not unique to Africa, and it has long been suggested that a culture of respecting elders could explain the predominance of relatively old leaders.
That may be so, but it is not without consequence.
African leaders have a proclivity to die in office, with often destabilising results.
When Malawi's Bingu wa Mutharika died in office in early 2012 his death was kept secret and his body flown around Africa as would-be successors plotted ways of staging a constitutional coup.
In the end the plots were averted and vice president Joyce Banda took power, but the risk was real.
Around the same time Guinea-Bissau suffered a very real coup after president Malam Bacai Sanha died in a Paris hospital. The country is still in crisis.
Alex Vines, of London's Chatham House, said the number of long-serving African leaders is reducing and those that remain have had to curb their ambitions.
"Following Arab Spring in North Africa, leaders like dos Santos have reconsidered ambitions for dynastic succession," even if others like Mr Obiang still favour that model.
"African leaders that have served over 30 years as leaders are increasingly rare."
"Where there are freer votes, we are seeing Africa's youth bulge play a role."