"Our analysis finds strong evidence that cutting taxes on the rich increases income inequality but has no effect on growth or unemployment" in the short and long term, the researchers wrote.
Low-income individuals are about twice as likely to delay retirement as their high-income counterparts.
The K shape suggests the wealthy are recovering and the lower-earning are not — jobs like restaurant staff, transportation workers, and cleaners are least likely to come back.
"Unlike the growth patterns in the 1950s and 1960s, the majority of full-time workers did not share in the economic growth of the last forty years."
While the top 5% of households benefited from a shrinking amount of competition, poorer households were forced to take on more debt just to keep up, researchers said.
In order to fall below the federal poverty line, one has to have an income at or below $12,000 or $26,200 for a family of four.