In May 2009, Meltzer warned that "the enormous increase in bank reserves—caused by the Fed’s purchases of bonds and mortgages—will surely bring on severe inflation if allowed to remain." Four years after Meltzer's comment, with the Fed's quantitative easing program still continuing, US inflation as measured by the consumer price index (CPI-U) was running at a year-on-year rate of 1.4%, while expected inflation over a 10-year period, as estimated by the Cleveland Federal Reserve, was running at around 1.55%. Meltzer's argument that nobody had expected the lack of inflation has been challenged by Paul Krugman.