I think you will find that:
1) Anarchies, almost by definition, spill into neighboring countries in the form of violence and/or refugess. This is the reason the U.N. intervenes in the first place.
2) A system of governance imposed by outsiders may be worse than anarchy, but self-governance, given a decade or more, will result in conditions better than anarchy. Indeed, I believe that left alone, an anarchy over time will develop into some form of stable government. Usually it's a dictatorship but there is a small chance it may be some form of self governance.
These are both as yet unproven claims based on my intuition of course. If someone has data to back these up or refute them, that would be really interesting.
I, too, wish there was better data on this.