John Campbell on Mortgage Market Design

John Campbell writes about Mortgage Market Design

"Although the US has roughly average levels of homeownership (67%) and mortgage debt
(72% of GDP), it is unusual in two other respects. Figure 3 plots the average number of
years that a mortgage carries a fixed rate. The lowest values (around 1 year) are in southern European countries such as Portugal, Spain, and Italy, where adjustable-rate mortgages predominate. The UK and Ireland similarly rely heavily on adjustable-rate mortgages.The average fixed-rate period is 5 years in Canada, 7-10 years in Belgium, France, and Germany, almost 20 years in Denmark, and 27 years in the US reflecting a roughly 90% market share for 30-year nominal fixed-rate mortgages. These instruments, which are taken for granted in the US, are anomalous within the global mortgage system.

"Figure 4 plots an index of government participation in housing finance, constructed by
the IMF (2011), against the homeownership rate. The IMF index combines information on subsidies to home purchases, government funding or guarantees for mortgage loans, preferential tax treatment for mortgage interest or capital gains on housing, and the existence of a dominant state-owned mortgage lender. The figure shows that US housing policy is highly interventionist, more so than any other country illustrated except Singapore. The high value of the government participation index for the US results from subsidies to low and middle income homebuyers, subsidized mortgage guarantees by the government sponsored entities (GSEs), and favorable tax treatment of mortgage borrowing and housing capital gains. The main stated goal of much US housing policy is to increase the homeownership rate, but as previously noted the US has only average homeownership, and more generally there is only a very weak positive cross-country correlation between housing market intervention and
homeownership."
...
"I argue that there is a legitimate public interest in a stable, efficient mortgage system and call for deliberate experimentation with mortgage market design. Although our theoretical understanding of mortgage markets is still quite weak relative to the theory that underpins classic applications of market design (to auctions and matching problems, for example), financial theory and theoretically grounded empirical research will be important for this enterprise. Thus mortgage research offers financial economists an exciting opportunity to contribute to the well-being of society.