The Smithian

Accordingly, even if you “make it out” and arrive in the middle class…you will likely be less financially secure than a person that earns the same income but came from a middle class family. That person can put all of their extra money towards buying a home…retirement, additional degrees, starting a business, and sending their kids to college. But the poor person who earns a middle-class income might use a significant portion of their income keeping their parents’ heat on, helping their little brother go to college, or buying back-to-school clothes for their nieces and nephews. This makes it much harder for poor and working class people who become middle class to stay that way.

much more, here.