It requires at least a generation of explosive growth of the sort mustered by Japan, South Korea and China to eradicate extreme poverty. More recently, countries such as Vietnam and Bangladesh have reached economic escape velocity.

A sustained period of growth does not guarantee long-term success, as recent conflict in Ethiopia demonstrates. Nor, as China shows, does attainment of a certain standard of living necessarily lead to liberal democracy. But fast growth, reasonably equitably shared, remains a prerequisite for a better life.

Why do some countries remain poor while others stumble on a path to growth and development? This has been the subject of much academic study and many popular books. Jeffrey Sachs’ The End of Poverty emphasises the role of aid to deliver a “big push”, while Why Nations Fail by Daron Acemoglu and James Robinson sees a country’s institutions as a critical determinant of success or failure.