A series of papers by the Princeton economist Dani Rodrik and his colleagues tried to shed light on the impact of policy decisions on economic growth, but found that 'most instances of economic reform do not produce growth accelerations', and 'most growth accelerations are not preceded or accompanied by major changes in economic policies, institutional arrangements, political circumstances, or external conditions'. The economist William Easterly points out that the evidence for a change of leadership being the cause of a growth miracle anywhere in the developing world is wholly lacking: the timing simply does not match. The effect of leaders on growth rates, he says, is close to zero, a conclusion that is 'almost too shocking to be believed'. South