The study looked at how the rate of profit in the U.S. economy changed from 1975 to 2008. They found that the profit rate didn't really bounce back during this time. One big reason for this was that more non-production workers were being hired, which reduced the share of profits. This shift in the workforce happened because of changes in how things were made before the 1990s and how people were hired after the 1990s. Because profits stayed low for a long time, the U.S. economy started relying more on increasing the amount of money available, leading to a financial-focused way of making money in the country.