A very interesting video by Hans Rosling on how the worlds 200 countries have moved over the last 200 years to higher prosperity and life expectancy. The only issue is that many in the middle are averages, as he points out about china, and its really a straight line if you do finer subdivisions and the whole world will take another couple of centuries to reach the highs enjoyed by the western world today by which time the western world would have moved far far ahead.
I think the promise can only be delivered by technology. If technology can help bring down cost of medication and improve productivity of farms in the world, that will bring everyone up to almost the same level of health and on the basis of essential commodities PPP, also of wealth. My bet is on Technology as the great equalizer.
