It has become common for some economists to denounce the effect of low interest rates on fixed-income investors, but that is not the complete story. Certainly those with money to invest now face an unappealing set of choices. But those who bought long-term securities years ago — when inflation was expected to be considerably higher than it now is — are receiving more value than they expected.

The much discussed ratio of national debt to gross domestic product also suffers. Consider the 18 nations in the eurozone. Collectively, their national debts rose by 7.8 percent in 2012 and 2013, forcing up the debt-to-G.D.P. ratio by 5.2 percentage points. From 2004 to 2006, their debts rose nearly as rapidly, by 7.4 percent. But the debt-to-G.D.P. ratio actually fell by a percentage point. At the time, European economies were growing and inflation was also pushing up the nominal gross domestic product figures. Now there is little if any growth or inflation, and the result is to worsen the debt picture.

The markets inferred from the Fed’s statement that credit tightening through higher interest rates would more likely arrive sooner than expected, and the dollar rose. If the economic growth and job figures continue to look good, and if inflation manages to rise at least a little, that forecast could be a good one.

But what will happen if inflation — and inflation expectations — do decline? So far, as can be seen in the Survey of Professional Forecasters conducted quarterly by the Federal Reserve Bank of Philadelphia, the 10-year inflation forecast has remained stable at 2 percent. If it began to fall, that would catch the attention of Fed officials.

But the bond market is not so confident. The market inflation forecast can be estimated by calculating the inflation rate at which a purchase of a normal Treasury security would be no better or worse than the purchase of an inflation-protected Treasury security of the same maturity. At the end of last year, the 10-year inflation forecast was 2.2 percent; now it is 1.9 percent. The one-year forecast then was 1.5 percent; now it is a forecast of deflation, negative 0.75 percent.

What could the Fed do if it turns out deflation is a real threat? In theory, it could resume quantitative easing. It could also jawbone Congress to provide more fiscal stimulus. If the Republicans win control of the Senate in next week’s elections, the first alternative might bring angry denunciations from both sides of Capitol Hill. The second might simply be ignored.

As long as deflation is a possibility, the Fed would be well advised to explain, again and again, why inflation that is too low is also bad for the economy. The lesson that high inflation is a threat is well known to politicians and voters. There is a need, as Cardinal Wolsey might have said, to get something else into their heads.