The Federal Reserve directly controls the short-term interest rate. But what it really tries to target is inflation and its expectations. The Fed’s goal is to achieve the target of 2% inflation in the long-term, and its preferred price index is the core personal consumption expenditure price index that excludes the volatile food and energy sectors (or core PCE for short). So how has the Fed performed in achieving its target of 2% inflation in the past 15 years?

The chart above plots the implied core PCE index if inflation had met its 2% target (red line), and the actual core PCE index (blue line) starting from 1999. The blue line is consistently below the red line, the gap has only diverged further since the Great Recession. The cumulative effect is that today the price level is 4.7% below what it should have been had the Fed achieved its long-run target.

The divergence between target and actual inflation is all the more striking given the elevated rate of unemployment during the sample period. We have discussed in a previous post how the post-2001 and post-2009 recoveries were “jobless” – a recovery in output but not much in employment. The Fed has a dual mandate – inflation targeting and maximizing employment. It is traditionally believed that there is a trade-off between the two and a higher level of unemployment permits the Fed to go beyond its 2% inflation target (this is the famous Taylor rule). Yet the Fed has failed to achieve its target inflation despite high unemployment rates.

It is hard to fault the Fed for not trying – it brought short term rates to zero for an extended period of time, and bought trillions of dollars in bonds. Yet the gap between the red and blue lines continued to diverge.

The Fed’s difficulty in maintaining a 2% target is not just about the Great Recession. The divergence started in the 2000′s despite the Fed keeping nominal rates quite low by historical standards. In fact the only period when the blue line runs parallel to the red (implying a 2% rate of inflation for a while) is the 2004-2006 period when the economy witnessed an unprecedented growth in credit.

In ordinary times we should have seen run-away inflation given the rate of credit extension and spending against it (more on this soon). But we do not live in ordinary times anymore.

What we are witnessing is the limit of what monetary policy alone can do. Sometimes there is a tendency to assume that the Fed can “target” any inflation rate it wishes, or that it can target the overall price level – the so-called nominal GDP targeting. The evidence suggests that the Fed may not be so omnipotent.

The problems relating to below-target inflation are deeper and more structural. We discuss these issues in more detail in one of the chapters of our forthcoming book.