The clock is ticking, as they say. The Federal Reserve’s last chairman, Ben Bernanke, famously said that “We’ve been very, very clear that we will not allow inflation to rise above 2 percent. We could raise interest rates in 15 minutes if we have to.” Mr. Bernanke never got around to it, and Chairman Yellen is signaling she’s in no great rush, either. The New York Times’s story about what it calls “the most significant speech yet in her still-young Federal Reserve chairmanship” runs under the headline “Janet Yellen Signals She Won’t Raise Rates to Fight Bubbles.”

Well, Mr. Bernanke had to be referring to fifteen fiat minutes. What is 15 minutes, anyhow? Is it 900 seconds? Or 9,000 seconds or nine months. Our sense is that it’s a kind of floating 15 minutes, to be cashed in whenever the market will bear it. That must have been what Mr. Bernanke meant. Mrs. Yellen, for her part, is described by the Times as believing that “it would most likely be a bad idea to raise interest rates to fight financial excesses. Her focus, crucially, is not on preventing Wall Street from having ups and downs, but on making sure that those ups and downs don’t bring economic disaster.”

The writer for the Times — we’re quoting Neil Irwin here — reckons that Mrs. Yellen’s “focus on resilience differs from much of the public discussion, which often concerns whether some particular asset class is experiencing a ‘bubble,’ and whether policy makers should attempt to pop the bubble. Because a resilient financial system can withstand unexpected developments, identification of bubbles is less critical. As global financial markets continue their five-years-and-counting rally, urged along by policy from the Fed and other central banks, worry has been rising that the seeds are being sown for the next crisis.”

Mrs. Yellen was rolling her words at an event at the International Monetary Fund in Washington. She was also speaking in the wake of the release of a report by the Bank for International Settlements that, as Mr. Irwin puts it, “essentially accuses its own members of fecklessness in their easy-money policies.” The Wall Street Journal, in its editorial on the BIS report, got to the issue ahead of the Times and did it under a classic headline, which summed up what the bank for central bankers was saying as “Stop Us Before We Kill Again.”

The new Fed chairman, the Times reports, “doesn’t absolutely rule out using interest rate policy as a tool to combat financial excess.” But she is “making clear it is a less than optimal option.” It characterizes what Mrs. Yellen was doing as “putting banks and everyone else in the financial world on notice: The Fed is not going to protect you from making mistakes. It is just going to try to ensure that if you do make them, the rest of us won’t pay the consequences.” When she’s going to do that she doesn’t say. She wants her own 15 minutes of fame at a time of her own choosing.