'These markets will have the same share as Japan in 2009,' he said.

The top economies in 2050 are very likely to be China, followed by the US and India. Far behind come Japan, Brazil, Russia and then the EU, according to de Marcillac.

'But it is also possible that India will be number one,' he said.

Caveats that could hold the emerging markets back include inflation, insolvency, inefficiency, insurrection, inept administration, corruption and lack of infrastructure, he said.

De Marcillac foresees significant changes in IT as we know it today. For example, datacentres will move towards virtualization and service-oriented architecture. Trends in the software area are new business models, software for rent and development of open source. Phone, IP and mobility networks will converge, as will clients.