Emboldened by his victory over Donald Trump, Mr. Biden made clear he believed he had a mandate to effect broad change. Haunted by the response to the 2008 economic crisis, deemed too timid by many experts, his mantra has been that it is better to do too much rather than too little. Maybe — but this much?

The original sin was the $1.9 trillion American Rescue Plan, passed in March. The bill — almost completely unfunded — sought to counter the effects of the Covid pandemic by focusing on demand-side stimulus rather than on investment. That has contributed materially to today’s inflation levels.

Focused on the demand side, even most pessimists — me included — missed a pressing problem. Supply-chain bottlenecks have led to shortages of many goods, a crisis that has been exacerbated by the reluctance of Americans to return to work. The worker shortage has also hurt the service sector. Many restaurants, for example, remain closed because they can’t find workers. Both also spark higher prices.

Now, between the government payments and underspending during the pandemic, American consumers are sitting on an estimated $2.3 trillion more in their bank accounts than projected by the prepandemic trend.