Basically, if you're born with riches you will continue to live that way but if you were born in poverty or middle income you will continue on that path as well. Very few transition from middle to high class.
International Level: New Activist / Political Participation: 18 1.8%
$75k income not enough to keep a third of US households from living paycheck-to-paycheck:
A third of higher income Americans are living paycheck-to-paycheck, even when they earn $75,000 a year because they would rather spend money on eating out and experiences than save money for retirement, according to a new survey. Ref. Source 3
Law of physics explains natural drivers of wealth inequality
A engineering professor has proposed an explanation for why the income disparity in America between the rich and poor continues to grow. According to the constructal law of physics, income inequality naturally grows along with the economy. Ref. Source 9y.
Worry About Hunger, Homelessness Up for Lower-Income in US;
Over the past two years, an average of 67% of lower-income U.S. Adults, up from 51% from 2010-2011, have worried "A great deal" about the problem of hunger and homelessness in the country. Ref. Source 8g.