The Federal Reserve has raised interest rates six times this year in its effort to lower inflation—currently at 7.7%—to what it considers to be the ideal level of 2%. But how did the central bankers decide that 2% is ideal rather than some other number? It’s a question several Fed critics have raised. On Friday, Bank of America was the latest to weigh in on the matter, saying bluntly, “there is nothing special about 2%.” The Fed has company in its 2% inflation target. Several countries have the same target, seemingly giving more confirmation that 2% is perfect. Bank of...