A senior executive from one of London’s leading investment managers returned from a trip in the Middle East bearing good news. Business had been brisk but the real excitement was the discovery of a new market. These do not come along very often.

A report last year concluded this country has “strong fundamentals and impressive potential”, and for good reason: it is the third largest oil producer in Africa, with the largest proven oil reserves on the continent; real GDP growth is forecast to rise from last year’s 2.1% to 5.4% this year; its current gross domestic product of $60 billion is projected to exceed $250 billion by 2020; and its central bank is currently sitting on reserves of almost $50 billion.

Samir Gadio, an economist at Renaissance Capital, and author of the report, says the country has delivered “strong broad-based macro-economic growth in recent years,...