Thank you to readers for commenting on the question of cocoa processing - I stand corrected! In fact, Côte d'Ivoire isn't just the world's largest cocoa producer, but the third-largest processor (only just behind the Netherlands and the USA). Ghana, though much smaller with less than 100,000 tonnes of capacity right now, is catching up - ADM and Cargill have gleaming new factories under construction.
It seems that tax incentives do the trick, along with the comparatively cheap energy and transport out of the coastal ports - great news for anyone working there. I'd be interested to know what the CID folks make of this. Are the tax incentives a good use of resources? Presumably yes, if two conditions are met: (1) cocoa processing has positive externalities that give it a social benefit over and above the direct jobs/profits and (2) the processing wouldn't have happened without the tax incentives. I can see lots of good spillovers from cocoa processing, so this is probably a good deal for the governments concerned.