由于美國推出的“舊車換現(xiàn)金”計劃提振了消費支出，而美國制造商也在增加生產(chǎn)，經(jīng)濟學家們對美國今年下半年的經(jīng)濟增長情況做出了更為樂觀的預期。

　　在美國政府上周公布了第二季度國內(nèi)生產(chǎn)總值（GDP）數(shù)據(jù)后，經(jīng)濟學家們紛紛開始修正自己對美國經(jīng)濟增長情況的預期。數(shù)據(jù)顯示，美國經(jīng)濟今年第二季度較上年同期下降1%，降幅低于預期。上調(diào)對未來經(jīng)濟增長預期的勢頭本周仍在持續(xù)，因為人們認為美國政府的汽車銷售刺激計劃有望在未來幾個月增加消費者支出，并迫使汽車制造商較原計劃生產(chǎn)更多新車。

　　美國商務部（Commerce Department）周二宣布，6月份的消費者支出增長了0.4%.但經(jīng)通貨膨脹因素調(diào)整后，當月的消費者支出為下降0.1%.6月份的個人收入也下降了1.3%，創(chuàng)出四年來的最大單月降幅。

　　這一數(shù)據(jù)顯示，由于就業(yè)市場疲軟，美國消費者今年上半年承受了很大壓力。這種狀況暗示，人們期待中的GDP增長將不足以明顯降低失業(yè)率。

　　不過現(xiàn)在出現(xiàn)了本輪金融危機開始以來最大一波上調(diào)GDP預測值的浪潮。瑞銀（UBS AG）現(xiàn)在預計，美國經(jīng)濟第三季度將增長2.5%，高于此前預計的2%，第四季度將增長3%，高于此前預計的2.5%.富國銀行（Wells Fargo & Co.）也將它對美國第三季度經(jīng)濟增長率的預測值從2.2%上調(diào)至3%.它還將美國第四季度經(jīng)濟增長率預測值從1.6%上調(diào)到2.0%.T. Rowe Price Group Inc.則將它對美國第三季度經(jīng)濟增長率的預測值從1.3%上調(diào)到2.75%.

　　經(jīng)濟學家們此前已經(jīng)預計，隨著企業(yè)在今年上半年逐步消化庫存，美國的經(jīng)濟增長率未來幾個月將出現(xiàn)反彈。本周一份令人鼓舞的制造業(yè)報告顯示，受這一預期推動，美國的新訂單和工業(yè)生產(chǎn)都出現(xiàn)了躍升。

　　穆迪經(jīng)濟網(wǎng)（Moody's Economy.com）的首席經(jīng)濟學家贊迪（Mark Zandi）說，庫存減少和銷售增加這兩個因素結(jié)合在一起，構(gòu)成了人們至少對今年下半年的經(jīng)濟增長抱更樂觀看法的基本理由。該公司將它對美國今年第三季度經(jīng)濟增長率的預測值從1.1%上調(diào)到1.6%，將其對第四季度經(jīng)濟增長率的預測值從0.2%上調(diào)到了2.1%.

　　富國銀行的高級經(jīng)濟學家魏特納（Mark Vitner）說，如果美國國會批準將政府對“舊車換現(xiàn)金”計劃的補貼增加20億美元，汽車銷售甚至可能進一步提振消費者支出。但這也有可能導致美國的個人儲蓄率再次下降。美國6月份的儲蓄率已由前月的6.2%下降至4.6%.

　　不過，MFR Inc.的首席經(jīng)濟學家夏皮羅（Joshua Shapiro）則認為，一旦美國消費者不是在從政府的刺激計劃中獲得好處，美國的消費基本面仍會非常嚴峻。夏皮羅原本預計，美國經(jīng)濟今年第三季度將增長0.2%，第四季度為零增長，但他現(xiàn)在預計下半年的經(jīng)濟增長率有可能達到2%.

　　在“舊車換現(xiàn)金”計劃停止實施后，美國消費者有可能再度抑制支出，而長期來看美國的儲蓄率預計會繼續(xù)攀升。

　　美國經(jīng)濟持續(xù)增長的最理想情況是，經(jīng)濟在下半年表現(xiàn)強勁，消費者支出和消費者信心增加，而沒有再出現(xiàn)這次經(jīng)濟衰退以來的大規(guī)模裁員。否則的話，經(jīng)濟要繼續(xù)增長，就必須借助企業(yè)投資的回升。雖然新訂單數(shù)據(jù)正在顯示令人鼓舞的跡象，但目前還沒有什么跡象顯示經(jīng)濟的各個領域已普遍出現(xiàn)了增長。

　　雖然人們并不認為住房市場會帶動經(jīng)濟復蘇，但這一領域的改善跡象卻有可能推動經(jīng)濟增長。美國全國地產(chǎn)經(jīng)紀商協(xié)會（National Association of Realtors ）周二宣布，用以衡量購房簽約情況并預測成屋銷售情況的成屋待完成銷售指數(shù)今年6月上升3.6%，達到94.6點，為2007年6月以來的最高點位。這一指數(shù)暗示，成屋銷售情況未來一到兩個月預計會出現(xiàn)改善。不過，該指數(shù)最近一直不大能準確預示成屋銷售的實際情況。

　　Economists are predicting a brighter second half of the year as the cash-for-clunkers program boosts spending and U.S. manufacturers ramp up their production.

　　Revisions began after last week's gross-domestic-product report， showing the economy contracted at a better-than-expected 1%. This week， the upward revisions have continued on hopes the government's auto stimulus program would propel consumer spending in coming months and force auto makers to make more new cars than previously planned.

　　Meanwhile， the Commerce Department said Tuesday that consumer spending rose 0.4% in June. But adjusted for inflation， it fell 0.1%. Personal-income data also fell 1.3% in June， the largest single-month drop in four years.

　　The data indicated that consumers concluded the first half under intense pressure from a weak labor market. That suggests the anticipated GDP growth won't be enough to substantially bring down the unemployment rate.

　　Still， in the largest wave of upward revisions of GDP forecasts since the financial crisis began， UBS AG is now predicting 2.5% growth in the third quarter， up from 2%， and 3% growth in the fourth quarter， up from 2.5%. Wells Fargo & Co. also revised its third-quarter forecast to 3% growth， up from 2.2%. For the fourth quarter， it is now predicting 2.0%， up from 1.6%. T. Rowe Price Group Inc. increased its third-quarter projection to 2.75% from 1.3%.

　　Economists already had expected growth to rebound in coming months after companies drew down inventories in the first half of the year. A promising manufacturing report this week showed a jump in new orders and production， building on those expectations.

　　'When you combine leaner inventories with more sales， that's the fundamental reason for being more optimistic about at least the second half of this year，' said Mark Zandi， chief economist for Moody's Economy.com. The firm revised its third-quarter forecast to 1.6% from 1.1%， and its fourth-quarter outlook to 2.1% from 0.2%.

　　If the cash-for-clunkers program receives an additional $2 billion in funding from Congress， sales could boost consumer spending even further， said Mark Vitner， a senior economist at Wells Fargo. It would likely cause another drop in the personal savings rate， which fell to 4.6% in June from 6.2% a month earlier.

　　However， MFR Inc. chief economist Joshua Shapiro said， 'The underlying fundamentals for the consumer are going to remain pretty tough' once they aren't benefiting from government programs. Mr. Shapiro originally predicted 0.2% growth in the third quarter and no growth in the fourth quarter， but said now 2% growth is likely in the second half.

　　When the cash-for-clunkers program expires， consumers are likely to rein in spending once again， and the savings rate is expected to continue its climb in the long run.

　　The best-case scenario for sustained growth is a strong second half， with improved consumer spending and confidence， and without the massive layoffs that have marked much of the recession. Short of that， business investment would have to make a comeback for expansion to continue. New orders are showing encouraging signs， but so far there's little sign the growth is widespread.

　　Although housing isn't expected to lead the recovery， signs of improvement in the sector could buoy growth in the economy. The pending home-sales index， which measures housing contract activity and is designed to foreshadow existing home sales， increased 3.6% in June to 94.6 —— its highest point since June 2007， the National Association of Realtors said Tuesday. The measure suggests that existing home sales are likely to rise in the next month or two， though the relationship between the two indicators has been volatile lately.