Income Distribution Across the World's 7 Billion

This map is originally an interactive table from National Geographic.  Here are a few interesting observations I have after playing around with it on the National Geographic website:

• I am amazingly surprised to see most of Latin America classified as "Upper Middle Class," which would put them on par with Eastern Europe.  Not all that long ago, Latin America and Africa were in extremely similar economic situations, (At Least We're Not Africa, 8/16/2010).  What have Latinos done differently to separate themselves from the pack?
• The "Lower Middle Class" is expected to account for the largest percentages of population growth, not the lowest income group.
• As income increases, so does proportion of population living in urban areas.
• Although we don't know which is cause and which is the effect (likely both factors amplify the other -- connectivity increases income and income increases access to connectivity), but cell phone use, personal computer ownership, and internet access all increase as incomes increase.

Income Distribution Across the World's 7 Billion