“I am unaware of another Fed chair in history who has, so quickly and clearly, owned the policy uncertainties that the Fed confronts, including when the Fed has gotten it wrong,” said Peter Conti-Brown, a financial historian at the University of Pennsylvania’s Wharton School. “The strategy was to be the Wizard of Oz to the citizens of the Emerald City, not the man behind the curtain to the visitors from Kansas. Powell has opened the curtain and let us in.”

Consider a short narrative of the last two months.

Late May and June brought a weak report on the labor market, a plunge in some surveys of business activity, and market volatility as traders bet on Fed rate cuts. It looked like the first stage of a major downturn.

Mr. Powell essentially confirmed that lower rates were on the way in his mid-June news conference and subsequent public appearances.

But in the last few weeks, the economic weakness has come to look more like a short-term blip than a trend. The job market is quite healthy by any modern standard, according to the latest numbers, and overall growth for the quarter that just ended looks likely to be comfortably in positive territory. American consumers keep spending money, a reality confirmed by a good June retail sales number released this week.

As the economic data has firmed up, Mr. Powell has had opportunities to back away from the rate cut message, including in congressional testimony last week and a speech in Paris on Tuesday. He did not do so.