For months, beleaguered American consumers have defied expert forecasts that they would soon succumb to the pressures of falling home prices, fewer jobs and shrinking paychecks. Now, they appear to have given in.

On Wednesday, the Commerce Department reported that the economy continued to stagnate during the first three months of the year, with a sharp pullback in consumer spending the primary factor at play.

Pressures on households in which cash is tight appeared to weigh significantly in the calculations of the Federal Reserve as it rolled back interest rates Wednesday for the seventh time since September  this time by one-fourth of a percentage point  in a bid to prevent a further falloff in the economy.

The Fed made clear, though, that investors and borrowers should not expect another drop in interest rates anytime soon. In the statement accompanying their action, policy makers said they believed that with the short-term rate at 2 percent, they had already unleashed enough economic stimulus to “help promote moderate growth.”