The mortgage market is just one of many markets competing for funds in the overall marketplace for credit. As such, funds tend to flow across markets in response to increased demand. Interest rates in all markets are thus correlated, with differences depending on factors such as the risk to any particular sector of the economy. It turns out that the interest rate on mortgages is linked fairly closely to the interest rate on ten-year government bonds. The interest rate on 30-year mortgages averages about 1.7 percentage points above the interest rate on 10-year U.S. Treasury bonds, as Chart 4 shows. During the financial crisis, the difference between the two interest rates increased quite a bit because of the perceived risk to mortgage loans, ranging between 2 and 3 percentage points from November 2007 to March 2009, but has declined since. In May 2016, the interest rate on mortgages was about 3.6 percent, while the interest rate on 10-year government bonds was about 1.8 percent, so the 1.8 percentage point difference between the two was not much above the historical average of 1.7 percentage points.
Chart: Mortgage and Ten-Year Government Bond Interest Rates
Source: Federal Reserve Board data on interest rates
If we look at the total amount of mortgage debt outstanding as a percent of GDP (see chart), we see that it has grown steadily over time. Mortgage debt rose from 20 percent of GDP in 1955 to about 30 percent in 1965, and then stayed near 30 percent until 1985. In the 7 years from 1985 to 1992, mortgage debt grew another 12 percentage points to 42 percent of GDP. It didn’t rise much over the next 8 years, reaching 46 percent of GDP by 2000. But then the combination of low interest rates and sub-prime lending led mortgage debt to rise very sharply, hitting a peak of 73 percent of GDP in 2009. It has declined significantly since the financial crisis, dropping 21 percentage points from 2009 to 2015, standing at 52 percent of GDP in late 2015. But the level of mortgage debt outstanding relative to GDP is still far above where it was before 2000 when the housing boom accelerated, so it may still need to drop before the housing market is restored to full health.
Chart: U.S. Household Mortgage Debt as a Percent of GDP
Source: Federal Reserve Board data on mortgage debt, rescaled by author using GDP from Bureau of Economic Analysis
From an economic point of view, Chart 1 (in the last blog) is a bit misleading because a dollar in 1975 is worth a lot more than a dollar in 2015, thanks to inflation. To adjust for inflation, we can use a measure of consumer prices. The resulting chart of inflation-adjusted home prices (Chart 2) gives a different picture than Chart 1. You can see that, in inflation-adjusted terms, housing prices grew rapidly in the second half of the 1970s, were fairly stable in the 1980s and early 1990s, and then began rising rapidly again in the second half of the 1990s until 2007. But, beginning early in 2007, inflation-adjusted home prices began to decline substantially. Over the five-year period from the peak in 2006 to their low point in 2012, inflation-adjusted home prices declined an average of 6 percent per year.
The data in Chart 2 can also be used to answer the question: is investing in a home a good financial investment? The answer is a clear NO! Using the data and calculating the inflation-adjusted annual return on homeownership, from 1975 to 2015, home prices rose only 1 percent per year, far less than stocks and bonds over the same period. Even at their peak in 2006, inflation-adjusted home prices had appreciated only 2 percent per year. So, if you buy a home, you are buying it because it provides shelter, not because it is a great financial investment.
Chart 2: U.S. Home Prices (Inflation-Adjusted)
Source: Federal Housing Finance Agency (FHFA) All-Transactions Home Price Index, rescaled by author and adjusted for inflation using personal consumption expenditures price index from Bureau of Economic Analysis
In the housing bubble in the early to mid-2000s, sensible ideas about how much debt a home buyer should take on were ignored by everyone—bankers and homeowners. Both foolish lenders and greedy homeowners were swayed by the fact that home prices had been increasing substantially over the past 10 years. If we look at Chart 1 showing quarterly data on national housing prices, you can see why they might be fooled. The chart plots a measure of prices of homes nationwide from 1975 to 2015. In the chart, you can see that until 2007, national house prices had never declined for more than one quarter in a row, and had increased in every year; so both lenders and homeowners were fooled into thinking that homes were a safe asset. Second, the appreciation in house prices from 2000 to 2005 averaged 8% per year. This led lenders and homeowners into falsely thinking that a homeowner’s income and ability to pay were no longer relevant. After all, if the home appreciated by 8% per year, it would be easy to sell the home and pay off the mortgage without a loss to either side. So, lenders started making sub-prime loans, which allow people to qualify for loans at percentages well below standard rules, such as those that limit the monthly housing payment to be less than 28 percent of a household’s income, and limit the total of a household’s monthly housing payment and payment on other debts (credit cards or student loans) to be less than 36 percent of its income. Some loans were even known as NINJA loans (because the homeowner had No Income, No Job, and no Assets). Those loans relied entirely on the appreciation of the home to be valid; as the home appreciated in value, the homeowner would borrow even more to pay off the original mortgage loan. But all of this sub-prime lending turned out to be foolish because it relied on the continued appreciation of house prices. When home prices began to decline in 2007, panic set in. Everyone began to realize that these loans would never be paid off. The worst part of the story is that sub-prime loans had the potential to greatly increase the homeownership rate among low-income households, but after the bubble burst, that dream vanished. So, the main benefit of allowing sub-prime lending in the first place, which was to increase homeownership among the poor, actually made things worse.
Chart 1: U.S. Home Prices
Source: Federal Housing Finance Agency (FHFA) All-Transactions Home Price Index, rescaled by author
This is a blog with ideas for a book on using economics in daily life. The idea is that many people could benefit from ideas and data known by economists, but we economists do not always communicate them in ways that people can understand. Economists tend to talk to each other, instead. So, this blog is my attempt to remedy that. I’m starting with discussions about housing and mortgages.