Biden’s American Rescue Plan worsened inflation. The question is how much.

With President Joe Biden’s legislative agenda stalled in Congress, the American Rescue Plan — the $1.9 trillion stimulus bill Democrats passed in March 2021 — may stand as his biggest achievement.

But did it contribute to the country’s current inflationary mess?

The massive spending law, which included $1,400 checks for each person in a family, generous expansions to unemployment insurance and child tax credit benefits, and hundreds of billions in aid to state and local governments, was intended to help people in need and stimulate economic demand, and it did.

Some economists argue, though, that all this came at...