*north america
*south america
*africa
*australia
*asia
*europe
Average household income is not a very good indicator due to the distribution of income within a country. As an example, countries such as Equatorial Guinea have a GDP per capita (between $30,000-$50,000) which should indicate an average (mean) household income of between $50,000-$90,0000 but the majority of the people in the country live on less than a dollar a day since most of the money goes to the very rich.
A more accurate indication is "medium household income" (50% more and 50% less). However, even those figures are not tracked by any world organization (UN, World Bank, or CIA) so are difficult to find.
The following is a list of the medium household income for a few counties.
http://en.wikipedia.org/wiki/Median_hous…
You will notice that medium income is generally expressed in Purchasing Power Parity Dollars (PPP$) and not absolute dollars. This is common in many statistics such as GDP since it is considered a more accurate way of comparing wealth.
http://fx.sauder.ubc.ca/PPP.html
The following is a table of average (mean) and medium income in the US.
http://www.census.gov/hhes/www/income/hi…
OECD does track the mean and medium income of OECD countries (appears to be individual and not household income). The numbers are given in local currency so you will have to convert to absolute US$ to get a comparison (not very accurate since it is not PPP$). Select either mean or medium income from the popdown menu.
http://stats.oecd.org/Index.aspx?DataSet…
It will be very difficult to find information on all the countries that you desire.
The best way to compare wealth between countries (which is more readily available) is the GDP per capita of different countries. However, that can also be very skewed for rich small countries (populations less than 100,000 people) such as Liechtenstein, Burmeda, and Jersey since much of the economy is controlled by high GDP banking sector. Also GDP per capita does not indicate how the wealth is distributed. However, it is considered the best indication available for comparing wealth between countries even with its flaws.
http://www.indexmundi.com/g/r.aspx?c=mr&…