Evidence shows that after late 2021, U.S. officials and mainstream commentary quickly stopped using “transitory” as an active label for ongoing inflation and instead talked about the word itself in the past tense.

• In late November and early December 2021, Fed Chair Jerome Powell and Treasury Secretary Janet Yellen both publicly said it was time to “retire” the term transitory for inflation, signaling an official abandonment of the word as a descriptor of current price pressures.(fortune.com) Media coverage at the time framed this as officials no longer viewing inflation as “transitory.”(fortune.com)
• In 2022, commentary referred to the word mainly to note that it had been retired or misused (for example, a CNBC column titled that the Fed may have retired “transitory” too soon, explicitly treating it as a former label).(cnbc.com) This is consistent with the prediction that its popularity as a descriptor would fade.
• By 2024–2025, references by senior officials are explicitly retrospective and apologetic: Yellen says she regrets having called inflation “transitory,” explaining that to most people that implies only a few weeks or months, and she now distances herself from the term.(foxbusiness.com) A 2025 CNBC market brief even describes “transitory” as a term that “became taboo for Fed officials” after they got the inflation call wrong, underscoring that it is no longer part of their normal inflation vocabulary.(cnbc.com)

Across policymakers and the media, the usage pattern matches Sacks’s prediction: the word “transitory” briefly enjoyed heavy use for inflation in 2021 but was then publicly “retired” and largely vanished as an active descriptor in the following year or so, surviving mainly as a historical or critical reference. This makes the prediction essentially correct.