per capital income by country

per capital income tells, on average the wealth distribution between countries.
of course it tell nothing of the disparity in wealth within a country.

How big is the "middle class" of America compared to the "middle class" of Germany?
How big is the wealth gap in our favorite countries?

well, let's first take a look at out favorite countries at the following:
http://www.nationmaster.com/graph/eco_gro_nat_inc_percap-gross-national-income-per-capita

Here is a summary of our favorite countries:

#1. Luxembourg
2. Switzerland
3. Japan
4. Norway
5. USA
...

14. Germany
15. France
...

20. Italy
...

28. Spain