Why does wealth not trickle down to the poorer parts of the world?
Wealth sometimes do “trickle down” to some poorer parts. Usually, as money goes into those poorer parts, the richer parts gets richer and the cost of living increases. So having a little more money when things cost more doesn’t change anything. However, most parts of the world don’t get the wealth because (like Keith said) they do not have goods or services to offer for sale or most times they don’t have awareness of those goods and services. Then you factor in the incredible amounts of corruption in the governments of a lot of the poorer countries, then you can see why much progress isn’t being made. Generally speaking, the societies that can conform the most to modernity (industrialization, institutionalization, communication/media) usually gain a higher percentage of the wealth.