Now we have an economy in which asset values keep going up because we expect them to keep going up, and in which easy money is creating speculative bubbles that seem obvious to anyone not living inside of them. Rivian Automotive, to take an example, is an electric-vehicle maker that has been losing money hand-over-fist while delivering, as of November, a grand total of 156 vehicles. That month, it went public with a market cap just shy of $100 billion, larger than Ford’s or GM’s.

Hoenig was around the last time something like this happened, in the 1970s, when easy money encouraged bankers to underwrite increasingly risky loans while relying on increasingly inflated assets, like farmland and oil wells, as collateral. That helped lead to 1,600 bank failures when the asset bubble burst after Volcker’s rate increases.

Hoenig’s warning is that we might soon be staring into the teeth of something similar. Or worse. Federal debt held by the public was roughly 24 percent of G.D.P. when Volcker became chair of the Fed. It was 96 percent in the third quarter of last year. Corporate debt of nonfinancial businesses — at around $11.4 trillion — is nearly twice what it was on the eve of the Great Recession.