Pickett and Wilkinson have put together a very interesting study of the results of income inequality on societies. They examined the wealthiest countries in the world, comparing the top and bottom 20 percent for income, as well as all 50 US states. What they found in their comparisons, which use data from WHO, the Centers for Disease Control and numerous other reputable scientific organizations, is that those societies where income inequality is greater have increased social problems across the board.
Among the wealthiest nations, Japan was found to have the least inequality between the wealthiest and poorest, and the US and the UK to have the highest. Rates of such problems as lack of trust between people, mental health issues, teenage pregnancy, school dropout rates and crime were found to be higher along the same continuum as the income inequality scale. The continuum was identical among the 50 US states.
Pickett and Wilkinson found that countries or states which expended more public funds on education and welfare also had lower rates of the problems they studied, which flies in the face of the conventional wisdom that using funds in this fashion creates social problems. They provided some interesting possibilities for relieving the inequality gap, including employee ownership of companies and increase taxation of the super-wealthy.
Overall, this is a fascinating look at the sociology of income equality. The problems in unequal societies were not limited to those at the lower end of the spectrum, as one might expect, but were found all the way across the board. Well worth reading for those with an interest in sociology.