In an article reporting on a speech by Federal Reserve Board Chair Janet Yellen, the Post told readers:

"One of the puzzles currently confounding economists is why inflation has remained so low even as the recovery has picked up steam. The Fed set a 2 percent inflation target but its preferred measure of price changes shows inflation is about half that."

Actually economists are not at all confounded by why inflation has remained low. The predominant view of inflation is that the change in the rate of inflation depends on the level of unemployment. Since nearly all economists believe the unemployment rate is still above its trend level, they expect inflation to be falling, not rising. In fact the bigger mystery from the standpoint of standard economic models is why the rate of inflation has not fallen more. (The answer is that wages and prices tend to be sticky going downward.)

Anyhow, the confounding is only at the Washington Post. The low inflation rate is not something economists have trouble explaining.