(I write a monthly opinion piece for Barron’s. This one was published there in September.)
Almost everyone, it seems, now agrees that higher interest rates mean economic pain. This pain is usually thought of in terms of lost jobs and shuttered businesses. Those costs are very real. But there’s another cost of rate increases that is less discussed: their effect on balance sheets.
Economists tend to frame the effects of interest rates in terms of incentives for new borrowing. As with (almost) anything else, if loans cost more, people will take less of them. But interest rates don’t matter only for new borrowers, they also affect people who borrowed in the past. As debt rolls over, higher or lower current rates get passed on to the servicing costs of existing debt. The effect of interest rate changes on the burden of existing debt can dwarf their effect on new borrowing—especially when debt is already high.
Let’s step back for a moment from current debates. One of the central macroeconomic stories of recent decades is the rise in household debt. In 1984, it was a bit over 60% of disposable income, a ratio that had hardly changed since 1960. But over the next quarter-century, debt-income ratios would double, reaching 130%. This rise in household debt was the background of the worldwide financial crisis of 2007-2008, and made household debt a live political question for the first time in modern American history.
Household debt peaked in 2008; it has since fallen almost as quickly as it rose. On the eve of the pandemic, the aggregate household debt-income ratio stood at 92%—still high, by historical standards, but far lower than a decade before.
These dramatic swings are often explained in terms of household behavior. For some on the political right, rising debt in the 1984-2008 period was the result of misguided government programs that encouraged excessive borrowing, and perhaps also a symptom of cultural shifts that undermined responsible financial management. On the political left, it was more likely to be seen as the result of financial deregulation that encouraged irresponsible lending, along with income inequality that pushed those lower down the income ladder to spend beyond their means.
Perhaps the one thing these two sides would agree on is that a higher debt burden is the result of more borrowing.
But as economist Arjun Jayadev and I have shown in a series of papers, this isn’t necessarily so. During much of the period of rising debt, households borrowed less on average than during the 1960s and 1970s. Not more. So what changed? In the earlier period, low interest rates and faster nominal income growth meant that a higher level of debt-financed expenditure was consistent with stable debt-income ratios.
The rise in debt ratios between 1984 and 2008, we found, was not mainly a story of people borrowing more. Rather, it was a shift in macroeconomic conditions that meant that the same level of borrowing that had been sustainable in a high-growth, low-interest era was unsustainable in the higher-interest environment that followed the steep rate hikes under Federal Reserve Chair Paul Volcker. With higher rates, a level of spending on houses, cars, education and other debt-financed assets that would previously have been consistent with a constant debt-income ratio, now led to a rising one.
(Yes, there would later be a big rise in borrowing during the housing boom of the 2000s. But this is not the whole story, or even the biggest part of it.)
Similarly, the fall in debt after 2008 in part reflects sharply reduced borrowing in the wake of the crisis—but only in part. Defaults, which resulted in the writing-off of about 10% of household debt over 2008-2012, also played a role. More important were the low interest rates of these years. Thanks to low rates, the overall debt burden continued to fall even as households began to borrow again.
In effect, low rates mean that the same fraction of income devoted to debt service leads to a larger fall in principal—a dynamic any homeowner can understand.
The figure nearby illustrates the relative contributions of low rates and reduced borrowing to the fall in debt ratios after 2008. The heavy black line is the actual path of the aggregate household debt-income ratio. The red line shows the path it would have followed if households had not reduced their borrowing after 2008, but instead had continued to take on the same amount of new debt (as a share of their income) as they did on average during the previous 25 years of rising debt. The blue line shows what would have happened to the debt ratio if households had borrowed as much as they actually did, but had faced the average effective interest rate of that earlier period.
As you can see, both reduced borrowing and lower rates were necessary for household debt to fall. Hold either one constant at its earlier level, and household debt would today be approaching 150% of disposable income. Note also that households were paying down debt mainly during the crisis itself and its immediate aftermath—that’s where the red and black lines diverge sharply. Since 2014, as household spending has picked up again, it’s only thanks to low rates that debt burdens have continued to fall.
(Yes, most household debt is in the form of fixed-rate mortgages. But over time, as families move homes or refinance, the effective interest rate on their debt tends to follow the rate set by the Fed.)
The rebuilding of household finances is an important but seldom-acknowledged benefit of the decade of ultra-low rates after 2007. It’s a big reason why the U.S. economy weathered the pandemic with relatively little damage, and why it’s growing so resiliently today.
And that brings us back to the present. If low rates relieved the burden of debt on American families, will rate hikes put them back on an unsustainable path?
The danger is certainly real. While almost all the discussion of rate hikes focuses on their effects on new borrowing, their effects on the burden of existing debt are arguably more important. The 1980s—often seen as an inflation-control success story—are a cautionary tale in this respect. Even though household borrowing fell in the 1980s, debt burdens still rose. The developing world—where foreign borrowing had soared in response to the oil shock—fared much worse.
Yes, with higher rates people will borrow less. But it’s unlikely they will borrow enough less to offset the increased burden of the debt they already have. The main assets financed by credit—houses, cars, and college degrees—are deeply woven into American life, and can’t be easily foregone. It’s a safe bet that a prolonged period of high rates will result in families carrying more debt, not less.
That said, there are reasons for optimism. Interest rates are still low by historical standards. The improvement in household finances during the post-2008 decade was reinforced by the substantial income-support programs in the relief packages Congress passed in response to the pandemic; this will not be reversed quickly. Continued strong growth in employment means rising household incomes, which, mechanically, pushes down the debt-income ratio.
Student debt cancellation is also well-timed in this respect. Despite the fears of some, debt forgiveness will not boost current demand—no interest has been paid on this debt since March 2020, so the immediate effect on spending will be minimal. But forgiveness will improve household balance sheets, offsetting some of the effect of interest rate hikes and encouraging spending in the future, when the economy may be struggling with too little demand rather than (arguably) too much.
Reducing the burden of debt is also one of the few silver linings of inflation. It’s often assumed that if people’s incomes are rising at the same pace as the prices of the things they buy, they are no better off. But strictly speaking, this isn’t true—income is used for servicing debt as well as for buying things. Even if real incomes are stagnant or falling, rising nominal incomes reduce the burden of existing debt. This is not an argument that high inflation is a good thing. But even bad things can have benefits as well as costs.
Will we look back on this moment as the beginning of a new era of financial instability, as families, businesses, and governments find themselves unable to keep up with the rising costs of servicing their debt? Or will the Fed be able to declare victory before it has done too much damage? At this point, it’s hard to say.
Either way we should focus less on how monetary policy affects incentives, and more time on how it affects the existing structure of assets and liabilities. The Fed’s ability to steer real variables like GDP and employment in real time has, I think, been greatly exaggerated. Its long-run influence over the financial system is a different story entirely.
