<?xml version="1.0" encoding="utf-8"?> <letsmt version="1.0"> <head></head> <body> <s id="1"> <w id="w1.1">中美贸易不平衡的平衡观</w> </s> <s id="2"> <w id="w2.1">发自北京</w> <w id="w2.2">—</w> <w id="w2.3">—</w> <w id="w2.4">在2007年7月以前</w> <w id="w2.5">，</w> <w id="w2.6">大多数经济学家都认为全球增长的最重大威胁来自于全球贸易不平衡</w> <w id="w2.7">。</w> <w id="w2.8">他们觉得美国净外债与GDP比率的不断上升</w> <w id="w2.9">—</w> <w id="w2.10">—</w> <w id="w2.11">这是长期经常账户赤字所引发的后果</w> <w id="w2.12">—</w> <w id="w2.13">—</w> <w id="w2.14">将导致资金流入急剧减少</w> <w id="w2.15">，</w> <w id="w2.16">随之削弱美元</w> <w id="w2.17">，</w> <w id="w2.18">而后利率上涨</w> <w id="w2.19">，</w> <w id="w2.20">并最终令美国经济陷入危机当中</w> <w id="w2.21">。</w> </s> <s id="3"> <w id="w3.1">但这一设想却未能成为现实</w> <w id="w3.2">，</w> <w id="w3.3">事实上本次危机源自于美国次级贷款的崩盘</w> <w id="w3.4">，</w> <w id="w3.5">并当即将全球经济拖入了一场自1930年代以来最为严重的衰退当中</w> <w id="w3.6">。</w> </s> <s id="4"> <w id="w4.1">而大多数经济学家之所以无法预见到危机背后的真正经济驱动力</w> <w id="w4.2">，</w> <w id="w4.3">是因为他们对美国总债务的快速增长缺乏足够的关注</w> <w id="w4.4">。</w> <w id="w4.5">实际上他们把注意力都放在了美国的外债上</w> <w id="w4.6">，</w> <w id="w4.7">却忽视了家庭负债</w> <w id="w4.8">（</w> <w id="w4.9">抵押贷款和消费者债务</w> <w id="w4.10">）</w> <w id="w4.11">、</w> <w id="w4.12">公共负债</w> <w id="w4.13">，</w> <w id="w4.14">商业债务和金融债务等方面的问题</w> <w id="w4.15">。</w> </s> <s id="5"> <w id="w5.1">他们尤其应当对美国抵押贷款和消费者债务的可持续性给予更多的关注</w> <w id="w5.2">。</w> <w id="w5.3">在2007年</w> <w id="w5.4">，</w> <w id="w5.5">上述两项负债与GDP的比率已经上升到90</w> <w id="w5.6">%</w> <w id="w5.7">以上</w> <w id="w5.8">，</w> <w id="w5.9">而与此同时净外债的相关比率只有24</w> <w id="w5.10">%</w> <w id="w5.11">。</w> </s> <s id="6"> <w id="w6.1">当然</w> <w id="w6.2">，</w> <w id="w6.3">债务的不同组成部分也因各自的特性和资金来源而大不相同</w> <w id="w6.4">—</w> <w id="w6.5">—</w> <w id="w6.6">而其可持续性也是如此</w> <w id="w6.7">。</w> <w id="w6.8">但一国总债务的各个组成部分及其资助方式之间显然是有所关联的</w> <w id="w6.9">。</w> </s> <s id="7" /> <s id="8"> <w id="w8.1">这意味着两点</w> <w id="w8.2">，</w> <w id="w8.3">首先</w> <w id="w8.4">：</w> <w id="w8.5">来自不同融资来源的资金在某种程度上是可互换的</w> <w id="w8.6">：</w> <w id="w8.7">总债务中某项资金出现的赤字可以用原本提供给其他用途的多余资金来填补</w> <w id="w8.8">。</w> <w id="w8.9">其二</w> <w id="w8.10">，</w> <w id="w8.11">总债务中某一部分所导致的问题将对其他部分造成影响</w> <w id="w8.12">。</w>