Poverty

Walter Williams has an excellent article on connection between nations and wealth. Here's a sample:

There's no complete explanation why some countries are affluent while others are poor, but there are some leads. Rank countries along a continuum according to whether they are closer to being free-market economies or whether they're closer to socialist or planned economies. Then, rank countries by per-capita income. We will find a general, not perfect, pattern whereby those countries having a larger free-market sector produce a higher standard of living for their citizens than those at the socialist end of the continuum.

If you want to know more about the connection between economic freedom and prosperity check out the Heritage Foundation's Index of Economic Freedom.