Faced with a stagflationary shock, the Federal Reserve is on hold. Its next move will be dictated by inflation *expectations*, measured by the 5-year breakeven rate. If expectations remain anchored, the Fed can focus on growth; if they rise, aggressive rate hikes will follow.

The Fed's concern isn't just the current high inflation rate, but the risk that prolonged high inflation changes public psychology. If businesses and consumers begin to expect continued price hikes, they may become less price-sensitive, creating a self-reinforcing 'snowball' effect that makes inflation much harder to control.

When the prevailing narrative, supported by Fed actions, is that the economy will 'run hot,' it becomes a self-fulfilling prophecy. Consumers and institutions alter their behavior by borrowing more and buying hard assets, which in turn fuels actual inflation.

The Federal Reserve can tolerate inflation running above its 2% target as long as long-term inflation expectations remain anchored. This is the critical variable that gives them policy flexibility. The market's belief in the Fed's long-term credibility is what matters most.

While the direct impact of tariffs may be temporary, the elongated process risks making consumers and businesses comfortable with higher inflation. Combined with questions about the Federal Reserve's political independence, this could unmoor expectations and make inflation persistent.

Central bank credibility is a finite resource. By not fully stamping out inflation to its 2% target, the Fed depletes its credibility, making the next inflationary shock harder and more costly to control—a lesson from the recurring inflation of the 1980s.

Policymakers have transitioned from a world where 2% inflation was a ceiling to one where it's a floor. The primary battle is no longer preventing inflation from rising above 2%, but rather struggling to bring it down to 2%, which is now seen as the bottom of the acceptable range.

In any economic crisis, whether deflationary like 2008 or inflationary like today, a policymaker's most crucial asset is their credibility. Fed President Austan Goolsbee shares this lesson from former Fed Chair Paul Volcker, warning against making promises or statements that could be proven wrong, as it makes managing the crisis significantly harder.

The narrative of "well-anchored" inflation expectations is being tested by the oil shock. The 5-year breakeven inflation rate, a key market indicator, has risen 20 basis points from 2.4% to 2.6%. This indicates investors are beginning to price in higher inflation for longer, not simply looking through the shock.