The near-parity in the two types of debt is unprecedented in data going back to the 1970s.
That's good news for all the homeowners who locked in cheap loans.
The firm's economists cited a strong labor market and a rapid slowdown in inflation.
Soaring inflation in many economies has helped erode debt burdens measured against the size of economic output.
Global public debt is set to reach 91% of gross domestic product this year, some 7.5 percentage points above its pre-Covid level.
Most economists project inflation will slow to less than 3% by the end of 2022.
High inflation can be helpful for debtors.
The consensus among economists is that high inflation won't last long in the U.S.
economists find it hard to pin down what drives long-run interest rates.
There are plenty of cases to be made for and against predictions of a period of rising inflation.