Studies that support the claim that income inequalities/disparities are increasing ignore the fact that income/money/currency does not equal wealth. Money and wealth are not the same. Money does not hold intrinsic value and wealth implies a greater quality of life. For example, income inequality has been increasing, but quality of life (wealth) disparities have been decreasing. Anyone that assumes that the rich is getting richer on the backs of the middle class or the poor is making linear and static assumptions in a non-linear and dynamic environment. Every group of people in the United States has seen an increase in the quality of life over the past 200, 100, or even 20 years. The income gap may be widening, but the quality of life gap has been narrowing considerably. The middle and lower classes of today are far better off than the middle and lower classes of the past. To state otherwise would imply incredible ignorance or purposeful manipulation for political and/or ideological purposes.
The "lower class" of today lives a far better life (and a significantly longer life) than the "lower class" of 100 years ago - this is due to to a market system prevailing, and a socialist system being stifled and subdued. If the statists/socialists/Marxists had their way; our society would regress and the "lower class" (along with every other class) would be far worse off. The statists want you to believe that that there is a growing disparity in the wealth and quality of life amongst the "classes"; and this is an outright lie. There is a growing disparity in income/paper/currency; but this leads to a narrowing of the disparities in wealth and quality of life. Wealth (quality of life) is NOT the same thing as Income (paper currency).
Example: the richest 1% of our society (the "rich") may earn 50% of the INCOME, however the "rich" CERTAINLY do NOT own 50% of the housing; nor do they own 50% of the land. The "rich" CERTAINLY do NOT own 50% of the automobiles. The "rich" CERTAINLY do NOT consume 50% of the food. The "rich" CERTAINLY do NOT consume 50% of the water. The "rich" CERTAINLY do NOT consume 50% of the country's medical and health care resources. The "rich" CERTAINLY do NOT utilize 50% of the country's educational resources. Land, housing, automobiles, food, clean water, medical and health care resources, and educational resources equate to wealth and a higher quality of living. Those that wish to demonize the top 1% or "the rich" are attempting to mislead by using the rhetorical tactics of red herring politics.