In a contribution to an oD forum, I wrote that I would bet that Amartya Sen's general point about democracy and famine holds for Africa as much as anywhere else, and that the more democratic an African country is the less likely there is to be famine that kills.
Could the current situation in Malawi be seen as a test case for this? There may be a danger of looking through the wrong end of a telescope in the sense that the terms may be too abstract and remote. In Malawi, as elsewhere, one would need to break down what one really means by "democracy" - the strengths and weaknesses of formal institutions, media, civil society and so on - not to speak of the role of unelected international organisations.
Matthew Lockwood argues that de facto one-party states in Africa offer the best chance to contain patronage and create developmental states.