美6月零售销售下降，汽车销量减少，一些高技术企业警告到二季度末企业硬件和软件支出疲软。

　　美国经济从衰退中复苏还未满三年，最近出人意料的几份报告让人质疑美国经济复苏的力度。投行雷曼兄弟的美国经济分析师伊桑-S.哈里斯称其最近遇到的每一个客户都问同一个问题，即放缓是否会威胁美国经济。

　　因企业的利润数据让投资人失望，美国股市自6月底以来确实步履蹒跚。债券价格开始回升，经济显示某些脆弱性也让人们减轻了对通胀的恐惧。

　　高盛经济学家安德鲁-希尔顿表示：“未来几周公布的经济数据很有可能延续经济放慢增长的主题，通胀压力还存在，加上消费者需求有萎缩的趋势。我们认为工业领域会有温和减速现象。”

　　Retail sales slowed in June. Auto purchases declined. Several technology companies warned about weak software and hardware spending at the end of the second quarter.

　　Less than three years since the United States emerged from a recession, a patchwork of unexpectedly soft economic reports is raising doubts about the vigor of the recovery.

　　"At every client meeting I have,'' said Ethan S. Harris, chief United States economist at Lehman Brothers, "I'm asked whether a slowdown has hit the U.S. economy."

　　Indeed, stock prices have faltered since the end of June, as corporate earnings have disappointed investors. And bond prices have risen, as evidence of economic fragility has allayed fears that inflation will accelerate. The recent sluggish economic indicators have inspired a note of caution in forecasts which until now had been unabashedly bullish.

　　"Economic data over the next several weeks are likely to follow the theme of slower growth with continued inflationary pressures," wrote Andrew Tilton, an Goldman Sachs economist, in a note to clients. "In addition to a weaker trend of consumer spending, we expect some modest deceleration in factory sector activity."

　　But, despite the scattered straws in the wind, most economists remain confident that economic growth is not collapsing but is shifting to a lower, more sustainable rate.

　　"The economy has come off its peak in the last couple of months," said Martin A. Regalia, chief economist at the United States Chamber of Commerce. "People have dropped their forecasts to about 3.5 percent. That's still a pretty solid number."

　　As the nation has rebounded from the recession of 2001, the main theme has been the ability of consumers to continue borrowing and spending. Near record-low interest rates allowed homeowners to refinance their mortgages, taking money out of their homes to pay for renovations and all sorts of consumer durables. Dirt-low interest rates allowed auto companies and others to offer zero interest-rate loans to stimulate sales.

　　Eventually, this dynamic was expected to end, as the recovery took hold and interest rates started rising. But even as debt-financed consumption waned, most economists expected two new sources of growth to kick in. First, a rising number of jobs would increase the overall wage pie - helping maintain consumer spending. Second, businesses, which spent the earlier part of the recovery paying down the debt amassed during the dot-com boom, would again start investing in new equipment.

　　Rising oil prices, however, have complicated this switch. Spurring a jump in inflation and taking a big bite out of the wallets of consumers, rising energy prices have raised the question of whether, combined with higher interest rates, they could depress consumer spending before the new sources of growth could gather sufficient steam.

　　Signs of the end of consumers' exuberance have popped up in several areas. Year-over-year growth in spending slowed to 4.1 percent in May, in real terms, the slowest pace since January. And there is anecdotal evidence of dreary sales in June. At Wal-Mart Stores Inc., the nation's largest retailer, sales climbed 2.2 percent in the last month, the smallest gain in over a year. At The Gap Inc., the clothing chain, comparable store sales in June actually fell 2 percent after several months of strong results.

　　June was also sour for automakers. The General Motors Corporation reported sales that fell 15 percent and the Ford Motor Company reported an 8 percent drop from the same month a year earlier. Citing the "difficult new vehicle retail environment that we are operating in," AutoNation Inc., America's largest automotive retailer, trimmed its earnings forecasts for the second quarter.

　　The corporate sector has also shown some fragility. Business investment had perked up this year after being absent during much of the earlier recovery. But in the second quarter, corporate investment seemed to fall back.

　　New orders of nondefense capital goods, excluding aircraft, fell 2.1 percent in April and 3.5 percent in May. And business spending on technology has seemingly remained weak. Since the beginning of July, 32 technology companies have issued warnings of lower second-quarter profits, according to Thomson First Call, while only one has increased its earnings projections.

　　Against this weaker economic backdrop, the Labor Department's report of an abrupt slowdown in job creation last month, which was accompanied by a fall in the average number of hours in the workweek and a meager increase in hourly wages, raised a question mark over the standard account of the economy's evolution.

　　"Now the only real positive for the consumer is income and job growth," Mr. Harris at Lehman said. "If the labor market really slows down it would be a blow to the consumer and we could talk of growth slipping to below trend."

　　But it is still too early to make that call. Indeed, Mr. Harris and most Wall Street economists view the June employment report as an aberration, and believe job growth will return to a more robust growth trend in July. If this is true, the economic recovery might do fine. Other data foreshadowing emerging weakness might just be a function of the changing sources of economic growth; not a signal of its demise.

　　"We've gone from an economy on life support driven by super aggressive 'refi' to one driven by more traditional sources of consumer income, which are jobs,'' said Robert J. Barbera, chief economist at ITG/Hoenig. "In the transition, we may see a change in the sectors that do best.''

　　Many economic variables remain strong. Personal income, a major driver of consumer spending, is growing. Mortgage applications are still increasing. Home sales are at record levels. The Institute of Supply Management's Purchasing Managers Index - historically an accurate gauge of manufacturing activity - is indicating only a mild slowdown in the second half from a strong period of expansion in the first.

　　Moreover, with interest rates still near their all-time lows it is harder to build a case for a sudden economic retrenchment than to explain continued growth.

　　The economy "is firing on all cylinders and the structure of interest rates is still crazy easy," Mr. Barbera said. Given that backdrop, he added, "I'm willing to cast a blind eye to the past 30 days' data."