Doesn't World Vision work...? Aww
It's only a stopgap measure - it doesn't address the underlying causes. Mind you, it may have a role in changing the culture of a country (having contact and communication with those in a country with liberties and prosperity as a result) by the flow of information.
While sound economic institutions are a positive step in developing an otherwise impoverished country (take a look at Taiwan and South Korea over the last 100 years), these institutions do not address the issue of culture as
costargh mentioned. What this alludes to is
rejection of (sudden) change - a culture can take a long period of time to slowly change its ways, particularly if the method of thinking is quite ingrained.
Take Somalia for example, which is essentially an anarchy. The warlord vs. warlord warfare in the streets of Mogadishu is a true reflection of the tribal roots of their society. This is not dissimilar to other conflicts in the region.
Mind you, the market for mercenaries in Somalia is about as good as it gets, I've read.
The point is, you can't reasonably expect a free market to succeed where people have the thought process of 'I have a gun, I know what to do if some guy rips me off'. Or perhaps the notion of 'individual responsibility' where such responsibility is seen to be governed by who's the better shot at the AK47.
Change the culture first, then economic institutions will succeed.