One problem with gauging the economic outlook is that routine data releases contain plenty of conflicting information, too. Readings generally have improved, but only after a run of notable weakness, and employment and wages have held up well for many months. But other indicators, particularly related to manufacturing, have fallen, and earnings for the S&P 500 companies are forecast to increase just 1.2 percent this year, according to FactSet, after rising 20.2 percent last year.

Economic sluggishness isn’t confined to the United States, either. In its latest forecast, issued last month, the Organization for Economic Cooperation and Development warned that the “global economy has become increasingly fragile and uncertain, with growth slowing and downside risks continuing to mount.” The International Monetary Fund warned on Tuesday of the mounting global cost of America’s trade dispute with China, and on Monday, David Malpass, the World Bank president, said his organization would soon ratchet down its economic forecast for the year.

A worrisome sign of slowing American growth is the inverted yield curve. This has been a precursor of recessions in which long-term interest rates, such as those for the 10-year Treasury bond, are lower than short-term rates, like those on Treasury bills. The markets have been facing an inversion for much of the year, even if they have managed mostly to ignore it.

When the 10-year bond yielded less than three-month bills in March, it was dismissed because the event lasted only several days. The inversion reappeared in late May and has been present nearly every day since, reaching a gap of 0.52 percentage points on Aug. 28, according to the Federal Reserve Bank of St. Louis.

The average bond fund rose 1.8 percent in the third quarter, led by an 8.5 percent gain for specialists in long-term government issues.

In its report, the O.E.C.D. attributed the economic deterioration, which applied to nearly all of 20 countries studied, to “trade tensions and policy uncertainty.” The performance of the American economy and stock market may hinge on whether the trade dispute that President Trump is engaged in, especially with China, is resolved sooner rather than later.

The tariffs imposed on imports by the Trump administration raise prices paid by American consumers. A study by two economists, Kirill Borusyak of University College London and Xavier Jaravel of the London School of Economics, estimated that the tariffs could cost the average American household roughly $460 a year, if they remained fully in place for an extended period.