How best to close the digital divide, especially if you’re a developing country with finite resources and a lot of mouths to feed? India, Afghanistan, Haiti come to mind – each is at a different stage of development, but each is definitely not part of the developed world

Bjorn Lomborg, an adjunct professor at the Copenhagen Business School, suggests that they’re best off leap-frogging the developed world by going straight to mobile broadband. This would allow them to “avoid the need for expensive fiber-optic cables for the last mile’ – or access point – of the network,” he writes.

That makes eminently good sense. Mobile telephony is increasingly making old-style fixed infrastructure unnecessary. As the professor points out, three-quarters of internet users in China get online via mobile phones. That figure rises to four out of five in Ethiopia and Uganda.

He quotes a new analysis by Emmanuelle Auriol and Alexia Lee González Fanfalone of the Toulouse School of Economics. They calculate the cost of increasing mobile broadband about three-fold in developing regions – from 21% to 60%. It will take $1.3 trillion and will establish about three billion more Internet connections.

But, writes Professor Lomborg, “it will also increase GDP growth. By 2020, the benefits would be almost $500 billion annually, and would continue to rise each year. Over the coming decades, the total benefit would reach about $22 trillion. As a result, every dollar spent on mobile broadband in the developing world would yield an estimated gain of $17. That looks like a really smart investment.”

(Tomorrow: If it took the digital high road, life in Haiti would improve dramatically)