The explanations have been all lined up. During the pandemic, people and their families that were cramped in apartments while working and studying from home decided enough was enough. They needed more space. People who could now work from anywhere decided, "Why not?" And they moved to what they thought would be more pleasant surroundings.

At least, that was the story. Some research on the part of Fannie Mae suggests something quite different. What drove the flood of homebuying wasn't the aesthetics of pandemic life, although that was something of a factor. The real driver was money.

Federal pandemic aid and big injections of liquidity by the Fed, particularly in the form of a zero-interest rate policy, fueled the moves by both first-time and upgrade buyers. Toward the end of 2021, 30-year fixed rate mortgages averaged around 3% and personal savings were heavily bolstered while credit card debt came down, which would have improved credit ratings. Median days on the market dropped from 74 in 2017 to 46 in 2021.