
The US just announced that they are working on a plan to introduce 50-year mortgages. I don't know what this plan entails, but my first reaction to the headline was: “Yeah, this is a bad idea.” But then I thought to myself, why is a 50-year amortization period too long? And is there any magic to 25- and 30-year mortgages?
At the most basic level, you could think of it this way: the average life expectancy of both sexes in America is currently 78.4 years. That means the average American would need to buy a home — with a 50-year mortgage — at 28.4 years old in order to fully pay it off by the time they die. At that point, why not rent?
A more rigorous analysis of amortization periods would likely involve a myriad of trade-offs related to housing affordability, homeownership rates, asset-price stability, household debt, overall financial risk, and other factors. But the primary feature of a long-ass mortgage is that it's alleged to make homeownership more attainable.
The obvious benefit of a 50-year mortgage is that it lowers a borrower’s monthly payment. For example, an $800,000 mortgage at 6% would create the following payments:
25-year amortization: $5,154 per month
30-year amortization: $4,796 per month
50-year amortization: $4,211 per month
But it's important to keep in mind that this is a synthetic affordability solution. It does not address fundamental constraints such as land use, zoning, construction costs, and the overall supply of new housing. Here's an excerpt from a speech that Carolyn Rogers, Senior Deputy Governor of the Bank of Canada, delivered last year:
"...we need to resist the temptation to try to solve the housing affordability challenge by tinkering too much with the mortgage market... leaning too much on measures that reduce the short-term cost of financing could have long-term impacts on the financial health of households, the mortgage market and the economy."




374