????中國(guó)一位頂尖的經(jīng)濟(jì)學(xué)家發(fā)出警告，全球已陷入“美元陷阱”——美國(guó)的貿(mào)易伙伴國(guó)既缺乏可替代美元的貨幣選擇，也無(wú)法阻止美聯(lián)儲(chǔ)（Federal Reserve）印發(fā)更多美元。

????這意味著大量持有美元資產(chǎn)的國(guó)家——如中國(guó)，該國(guó)大約3萬(wàn)億美元的外匯儲(chǔ)備中大部分是美元資產(chǎn)——只能坐視資產(chǎn)貶值。也不能輕易地進(jìn)行貨幣多元化，因?yàn)檫@可能加速美元資產(chǎn)的縮水。

????現(xiàn)行國(guó)際貨幣體系“既缺乏穩(wěn)定性，也缺乏公平性”，中國(guó)國(guó)際經(jīng)濟(jì)交流中心的經(jīng)濟(jì)學(xué)家徐洪才寫(xiě)道。

????徐洪才的這番言論見(jiàn)報(bào)，時(shí)間正是二十國(guó)集團(tuán)（G-20）財(cái)長(zhǎng)會(huì)議于3月31日在南京召開(kāi)前。二十國(guó)集團(tuán)財(cái)長(zhǎng)將討論如何取代當(dāng)前以美元為中心的國(guó)際貨幣體系——這個(gè)問(wèn)題多年來(lái)一直困擾著經(jīng)濟(jì)學(xué)家和政策制定者們，隨著中國(guó)的崛起，這個(gè)問(wèn)題變得更為緊迫。

????此次會(huì)議召開(kāi)之際，美元指數(shù)正徘徊于近期低點(diǎn)附近，原因是美國(guó)經(jīng)濟(jì)困頓以及美國(guó)聯(lián)邦儲(chǔ)備委員會(huì)的擴(kuò)張性貨幣政策。雖然日本遭受了大災(zāi)，但過(guò)去一年美元/日元走低；即便是歐洲可能迎來(lái)新一輪耗資巨大、存在政治爭(zhēng)議的援助計(jì)劃，美元/歐元也未能走高。

????徐洪才在文章中建議，應(yīng)建立一個(gè)由國(guó)際貨幣基金組織（International Monetary Fund）等類(lèi)似機(jī)構(gòu)監(jiān)管的多儲(chǔ)備貨幣體系。他指出，（當(dāng)一種儲(chǔ)備貨幣貶值時(shí)，）國(guó)際貨幣基金組織可以發(fā)出警告，迫使相關(guān)國(guó)家采取干預(yù)措施，穩(wěn)定幣值。路透社（Reuters）認(rèn)為，這一提案不太可能得到西方人的認(rèn)可，西方人更贊成已實(shí)行幾十年的自由浮動(dòng)匯率體系。

????當(dāng)然，要解決這個(gè)已延續(xù)幾十年的問(wèn)題絕非易事。但《華爾街日?qǐng)?bào)》(Wall Street Journal)的一篇報(bào)道稱(chēng)，此次會(huì)議自由交換意見(jiàn)的氛圍可能不如以往。中國(guó)官員對(duì)于美元貶值和嚴(yán)格管制人民幣匯率的話題非常敏感，已敦促參與各方不要談?wù)撎窖髢砂稛嶙h的匯率問(wèn)題。

????雖然這似乎是個(gè)好辦法，但沉默并不能讓這個(gè)問(wèn)題自動(dòng)消失。

????A top Chinese economist warned that the world has fallen into a "dollar trap," as U.S. trading partners lack an alternative to the greenback and can't prevent the Federal Reserve from printing more money.

????The arrangement means big holders of dollars – such as China, which holds some $3 trillion of foreign exchange reserves, mostly in dollars – must sit idly by and watch as the value of their holdings erode. They can't lightly diversify out of dollars at the risk of accelerating the erosion.

????The setup "lacks both stability and fairness," wrote Xu Hongcai, an economist at the China Center for International Economic Exchanges.

????He made the remarks in a paper published ahead of Thursday's meeting of G-20 finance ministers in Nanjing. They will discuss what might replace the current dollar-centric system – a subject that has vexed economists and policymakers for years and has grown more pressing with the rise of China.

????The meeting comes at a time when the dollar index is near its recent lows, thanks to the stumbles of the U.S. economy and the expansive monetary policy of the Fed. The dollar is down over the past year against the yen in spite of a massive disaster in Japan, and has failed to appreciate against the euro even as the Continent stumbles toward another spring of costly, politically divisive bailouts.

????Xu, for his part, suggests moving toward a system of multiple reserve currencies overseen in part by the likes of the International Monetary Fund. He says the IMF could issue alerts that would prompt countries to intervene to hold the value of their currencies steady. Reuters notes that the proposal isn't likely to pass muster with Westerners who favor the free-floating system that has been in place for decades.

????There is no easy answer to a problem that has built up over decades, of course. But a report in the Wall Street Journal says the session promises to be even less of a free-flowing exchange of ideas than usual. Chinese officials are so sensitive on the subject of the weakening dollar and their tight control of their own currency, the yuan, that they have urged participants not to discuss the exchange rate issue that has been so heatedly debated on both sides of the Pacific.

????But as appealing as that may sound, giving this problem the silent treatment is not going to make it go away.