No one should be surprised that the Fed is tightening monetary policy and expects to tighten significantly further over coming years. Unemployment is less than 5 percent, consistent with normal use of resources. Inflation is approaching the FOMC’s 2 percent objective. And policy rates remain below what simple guides would suggest as normal.

A key issue facing policymakers today is whether the Fed’s new operational framework is working effectively to tighten financial conditions without creating unnecessary volatility. While the FOMC’s actions are occurring in a familiar macroeconomic environment, the legacy of the crisis makes raising rates anything but routine. The key difference is the size of the Fed’s balance sheet. Unlike past episodes, when commercial bank reserves were relatively scarce, today they are abundant.

This difference—reflecting a balance sheet that is over four times its pre-crisis level—creates technical challenges for the Fed. The traditional approach of using modest open-market operations (through repurchase agreements of a few billion dollars) to control the federal funds rate—became ineffective as reserves grew abundant. This meant developing an entirely new operational framework. The good news is that—up to now—the challenges of policy setting with abundant reserves have been very clearly met. While this may seem mundane, it is no small achievement. Much like plumbing, had the Fed’s new system failed, everyone would have noticed. At the same time, there are still challenges to face, so we’re not completely out of the woods....