为什么说中国经济泡沫有可能戳破美国银行系统？

    传统观点认为，中国对美国银行不构成太多的直接风险。没错，如果中国爆发金融危机或者陷入衰退（考虑到中国经济最近的年增长率仍然保持在7%，这一幕不会很快来临），那将对全球经济造成严重伤害。美国银行和美国经济将会感受到这种冲击。但从对华直接风险敞口的角度来讲，美国银行目前并不会面临巨亏的风险。

    根据债务评级机构惠誉公司(Fitch)上周发布的一份报告，美国银行对华直接贷款共计830亿美元。相对于美国银行业的规模，这并不是一个大数目。比如，仅摩根大通(JPMorgan Chase)一家银行的贷款总额就超过7,000亿美元。整个美国银行业拥有近15万亿美元的资产。对于美国银行来说，中国的风险权重依然不算大。

    但这种状况似乎正在发生改变。一年前，由于担心信贷泡沫，中国政府大幅提高了国内利率，减缓国内银行的贷款速度。这就使得中美之间产生一个巨大的利率差：美国的短期银行同业贷款利率大约为 0.50% ，而中国的短期银行贷款利率则高达5%。

    由此看来，如果一家机构从美国和欧洲借款，然后在中国放贷，它就很容易赚到钱。一段时间以来，这种交易一直在增长，但直到最近才引起关注。它有一定的危险性，至少对美国银行系统而言。

    过去一周左右的时间里，一些大银行一直在追查它们是否卷入了一起融资骗贷欺诈案：中国青岛港一家大宗商品交易公司向多位贷款人提供同一抵押品。这起案件已经揭示了一个事实——中国公司为获取利差收益而从海外借入的很大一部分资金是以大宗商品作为抵押品的贷款。

    高盛公司(Goldman Sachs)估计，过去4年来，大宗商品支持贷款已经导致1,100亿美元的外币涌入中国经济，这笔资金约占中国同期新增短期债务总额的三分之一。

    花旗集团(Citigroup)似乎是唯一一家沦为青岛港欺诈案牺牲品的美国大型银行。但大多数美国大银行都在从事大宗商品支持的贷款业务，而且最近越做越大。据彭博社(Bloomberg)报道，全球银行去年向大宗商品类企业发放了共计6,870亿美元贷款，尽管其中许多贷款直接发放给了公司，并且是用原材料担保的。摩根大通是向海外发放贷款最多的美国贷款人，贷款金额为579亿美元；其次是富国银行(Wells Fargo)，贷款金额为470亿美元。

    惠誉和其他评级机构在估算美国银行系统的对华风险敞口时或许没有考虑这些贷款中的很大一部分。比如，大宗商品支持贷款有时候被结构化为衍生工具或掉期交易。惠誉表示，它的美国银行系统对华贷款预测值并没有把衍生工具和信用担保计算在内。

    The conventional wisdom is that China doesn’t hold much direct risk for U.S. banks. Sure, if China were to have a financial crisis, and if it were to fall into recession — a long way to go, considering its recent annual growth of 7% — that would do serious damage to the global economy. American banks and the U.S. economy would feel that. But in terms of direct exposure to China, U.S. banks don’t stand to lose a lot.

    According to a report last week from debt rating agency Fitch, U.S. banks have a collective $83 billion in direct loan exposure to China. That isn’t very much in the scope of the U.S. banking sector. JPMorgan Chase JPM 0.00% , alone, for instance, has over $700 billion in total loans. The entire U.S. banking sector has nearly $15 trillion in assets. For U.S. banks, China is still not that big of deal.

    That appears to be changing, though. Fearing a credit bubble, a year ago, Chinese authorities sharply raised domestic interest rates to slow lending made by local banks. That opened up a huge gap between U.S. interest rates, which are around 0.50% for short-term interbank loans, and Chinese interest rates, which are 5% for short-term banks loans.

    And so it appears there is easy money to be made borrowing money from the U.S. and Europe, and lending it in China. The trade’s been growing for a while, but it has attracted attention lately. And it’s a bit dicey, at least for the U.S. banks.

    In the last week or so, a number of large banks have been trying to figure out if they were taken in a loan fraud scheme in which a Chinese commodities trading firm in the port of Qingdao pledged the same collateral to a number of lenders. The scheme has shed light on the fact that a large portion of the overseas lending that Chinese companies are doing to capture the interest rate spread has been with loans collateralized with commodities.

    Goldman Sachs estimates that commodities-based lending has resulted in an inflow of $110 billion of foreign currency into the Chinese economy in the past four years, or about a third of all new short-term debt in China in that time.

    Citigroup C -1.41% appears to be the only large U.S. bank that has fallen victim to the Qingdao fraud. But most large U.S. banks make commodities-based loans, and the practice has been growing recently. Last year, banks around the world lent $687 billion to commodities-based businesses, according to Bloomberg, though much of those loans were made directly to the companies and secured by raw materials. JPMorgan was the top U.S. lender worldwide, at $57 billion, followed by Wells Fargo WFC 0.37% , which gave out $47 billion.

    Many of these loans might not be factored in the estimates that Fitch and others have put together to calculate U.S. banks’ exposure to China. For instance, sometimes commodities loans are structured as derivatives or swaps. Fitch says its China loan estimates do not factor in derivatives or guarantees.