[An earlier version of this piece appeared in Forbes.com.] Changes in demand caused by the pandemic were, of course, a big part of the house price boom but two years of falling mortgage rates was the main reason house prices skyrocketed in 2020 and 2021. Rates fell from 4.9% in November 2018 to 2.7% in January 2021, the lowest rate ever on 30-year fixed-rate mortgages.