You're right, Scott. The middle-class shrinking is grossly misstated by the current measure of income inequality.
Income inequality has been rising since the 1970's, but there are problems with the way it's reported. Income inequality will always be overstated.
Here are some income distribution facts taken from the U.S. Census Bureau:
Household Income Group % of Total Income Income Range:
Lowest 20%-----3.4%------$0-18,500
Second 20%----8.7%------$18,500-34,738
Third 20%-------14.7%-----$34,738-55,331
Fourth 20%------23.2%----$55,331-88,030
Highest 20%----50.1%----$88,030 and up
The top 20% has roughly 14 times the total share of money than the bottom 20%. For a comparison, in 1971, the top 20% had only 11 times the share of total money than the bottom 20%.
But why is this? Here's why.
The steady increase in income inequality in recent decades is due largely to increased immigration. Between 1970 and 2000, foreign-born population in our great country increased from 9.6 million to 31.1 million. The percentage of the U.S. population that is foreign-born increased from 4.7% in 1970 to 11.1% in 2000.
Immigrants' median annual income is about 15% lower than native-born Americans. This is why the gap between the top and bottom groups has increased.
However, income is even more equally distributed after taking out taxes and in-kind (food stamps, medical assistance, etc.) transfer payments. The current measure of inequality is skewed by this lack of inclusion.
Higher incomes pay a higher percentage of their income in federal taxes, but in-kind transfers are received disproportionately by lower income households.
Another way that inequality is overstated is that the distribution of money income expressed above overstates the actual degree of income inequality by focusing on income distribution at one point in time.
A large chunk of the people in the lowest 20% of households are young people at the start of their careers. Most of these young people will move into higher income groups as their careers progress and they develop more human capital (developed ability that increases a person's productivity).
If career incomes were compared or if incomes were compared for households at the same career stage the gap between the highest and lowest would be much smaller.
Wealth distribution is also overstated. This is caused by the measure of wealth distribution comparing different people at different career stages. Comparing the wealth of a 60-year-old to the wealth of a 25-year-old overstates the inequality.
Wealth distribution is also overstated because human capital is NOT included in measuring wealth. For most people, their human capital is the most valuable asset owned. An example would be a 25-year-old recent Harvard Law School grad may have very little accumulated wealth in terms of physical assets, but the Harvard Law degree is very valuable human capital.
These are the causes of the continuing income inequality, which people might find interesting.
1. Natural ability: Some people are born with skills in math, music, or athletics. A person with a high level of marketable natural ability may earn a higher income than a person with a lower level of natural ability.
2. Human capital: Mean earning increase as education levels rise, but, again, a degree in chemical engineering and a degree in elementary education will have different earning potential in the marketplace.
3. Work and leisure choices: Contrary to popular belief rich people don't just sit back and make money off the backs of hardworking proletarians. Most people who've accumulated much wealth and have high earning potential have worked incredibly hard for it.
4. Risk taking: People differ in their willingness to take risks. An example would be that self-employed entrepreneurs make up a disproportionately large share of society's millionaires, but they also make up a disproportionately large share of those filling for bankruptcy.
5. Employment discrimination: This occurs when employees make hiring, promotion, and pay decisions based on factors unrelated to employee productivity.
6. Luck: A person can have good luck (winning the lottery) or bad luck (suffering a debilitating illness). Most people experience a mix of good and bad luck.
Hope this helps!