Interest rates have been dropping since the 1980s, but profits from investments have not. A study looked at various factors like labor force and productivity growth to understand this. They found that the decrease in interest rates is linked to a change in how risky people think productivity growth is. This means that people are able to borrow more money, which matches the increase in debt seen since the financial crisis. This goes against the idea that people are reducing their debt, as suggested by some experts.