Violence was in the air as the Malian elder and his strongest tribesman crossed the River Moa by canoe. Waiting on Tiwai Island were dozens of Sierra Leonean fishermen, seething with anger. The Malians had paddled through two countries to Sierra Leone, lured by the bountiful fish stocks here. But only the village chief on the east side of the river had been compensated for the fishery rights – no agreement was struck with his counterpart on the west bank. And now the Malians were allegedly hunting bush meat from the island, a reserve home to chimpanzees and the endangered pygmy hippopotamus. That threatened something worth much more than fish: the tourism potential of post-Ebola Sierra Leone.

This incident, witnessed by myself, passed off without bloodshed. But it exemplifies the pitfalls of the system of informal local government holding sway across much of sub-Saharan Africa. Resources are exploited rapaciously for bribes, with scant benefits for those whose environment – and earning power – is degraded. Chieftanomics, if you will.

In the Cameroon, Western logging companies frequently bribe chieftains for permission to fell ancestral forests.

“It’s a feudal system,” says Global Witnesses’s Reiner Tegtmeyer. “A chief might get two crates of beer, a motorbike and his house rebuilt.”

Or cash. A typical bribe nets a chief $7 for one moabi tree; its timber is worth $150 per cubic meter. And the moabi is host to caterpillars which are a major source of protein for villagers. Under Cameroon’s Community Forests programme, eight million hectares of forest will be logged in this way over the next three decades. There were 25 Community Forests in 2005 – now there are more than 300. So what is to be done?

“The legal systems are in place,” Mr Tegtmeyer despairs. “Yet I’ve never seen anyone prosecuted. Rural development is needed, but it’s easier for companies to deal with a single chief. It’s in everyone’s interest to maintain the system – except normal people.”

A grim picture – but far from unique. Half of the bottom 20 states in Transparency International’s corruption index are African. Yet it is caricature to suggest chiefdoms are all harmful. In Sierra Leone, for instance, chiefs are credited with turning the tide against Ebola.

“Ebola’s not just a biological phenomenon,” says Peter Harrington, of Tony Blair’s Africa Governance Initiative. “It’s a social phenomenon too. Ebola preys on the desire to touch each other. One of the challenges was convincing people to stop doing profoundly human things, like caring for a sick child.”

And many Liberians thought Ebola was a Western conspiracy.

“Radio jingles and billboards don’t change those attitudes,” says Mr Harrington. “It took trusted figures to say, ‘It’s real’.”

Those figures were the chieftains. But was there corruption?

“It’s a deeply embedded cultural system that the big guy takes the resources and divides them between his flock,” says Mr Harrington. “I’m sure there was plenty of that with Ebola money. Chiefs are an institution and institutions can be good or bad – but they were the only institution that could mobilise people in an emergency.”

The role of chieftains differs across Africa – but carbon copy malfeasance is identifiable the continent over. What public policy might make an ancient system of governance fit for modernity?

Michela Wrong, who has covered Africa for Reuters and the Financial Times, points to Kenya, where corruption was “out of control”.

A new devolved constitution established local councils with real power, real funds – and democratic accountability.

“At last people will see if money is being stolen and villas built at a local level,” she says. “I don’t think it’ll lessen corruption, but it will give more transparency. People will be able to see who’s doing the stealing.”