The child mortality rate, of course, is directly tied to the standard of living that a culture experiences.

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Rwanda's child-mortality rate more than halved between 2005-06 and 2010-11.

ECONOMIST: African child mortality

Twelve had falls of over 4.4% a year, which is the rate of decline that is needed to meet the millennium development goal (MDG) of cutting by two-thirds the child-mortality rate between 1990 and 2015 (see chart).

ECONOMIST: African child mortality

According to Mr Demombynes and Karina Trommlerova, also of the World Bank, 16 of the 20 African countries which have had detailed surveys of living conditions since 2005 reported falls in their child-mortality rates (this rate is the number of deaths of children under five per 1, 000 live births).

ECONOMIST: African child mortality

Three countries Senegal, Rwanda and Kenya have seen falls of more than 8% a year, almost twice the MDG rate and enough to halve child mortality in about a decade.

ECONOMIST: African child mortality

High-mortality Liberia actually saw impressive GDP increases whereas Senegal, whose record in child mortality is second to none, had a rather anaemic growth rate by recent African standards (3.8% a year, half that of Rwanda).

ECONOMIST: African child mortality