For the fourth month in a row, inflation is stuck at 1.2 percent, just barely above the lowest levels ever recorded and the longest spell of such low inflation since records have been kept.

At least that’s the case if you look at inflation as measured by the personal consumption expenditures index and take out the food and energy components. This inflation statistic was published by the Bureau of Economic Analysis Friday morning. Headline inflation, meaning inflation including food and energy, was also low, but it increased from 1.3 to 1.4 percent.

Core inflation remaining at 1.2 percent is significant because it shows that inflationary pressures remain weak in the United States, despite the Federal Reserve’s efforts to expand the money supply. It is also relevant for the Fed’s looming decision at its upcoming Sept. 17-18 meeting on whether to scale back its large-scale bond-buying program.

The Fed has a target for inflation of 2 percent, and Chairman Ben Bernanke has said that the Fed will defend that target “from below” if necessary, meaning that it will hold off on slowing the pace of its stimulus or even increase it if necessary to ensure that inflation doesn’t fall too low. But members of the Fed also have said that they see the recent low inflation readings as transitory and expect it to pick up in upcoming months.

After a week in which the reading for second-quarter gross domestic product growth was revised up from 1.7 percent to 2.5 percent and the number of new claims for unemployment benefits remained low, continued low inflation would seem to be the one missing piece of the puzzle for the Fed to taper its asset purchases at its next meeting.

The PCE index inflation statistics were published Friday morning in a release on Personal Income and Outlays for July produced by the BEA. The report showed personal income and consumer spending both slowing from the month before and disappointing analysts. Private wages and salaries actually decreased by $15.3 billion in July, and government workers’ wages and salaries fell by $6.4 billion.