You don’t hear much these days about capital outflows from China. The renminbi seems well behaved, and China’s foreign exchange reserves have stayed stable in the past couple of months. Sure, the economy itself faces a bunch of challenges, as the government hasn’t quite found a way to maintain rapid growth rates without a dangerous degree of reliance on credit. But you don’t get the sense that the Chinese are falling over themselves in a rush to buy dollars.

这些天你没有听到太多关于中国资本外流的消息。人民币似乎表现良好，中国的外汇储备在过去两个月里保持稳定。当然，中国经济本身面临诸多挑战，中国政府还没有找到方法保持经济快速增长而不使信贷依赖达到危险水平。但你没有中国人正在争先恐后地购买美元的感觉。

The Fed might take heart from this. On two occasions in the past year, the US Federal Reserve’s intentions to raise interest rates have been confounded by financial turbulence caused by large outflows from China. The first was last summer, when the Fed was forced to postpone rate hikes following a surge in flows from China after the People’s Bank of China (PBoC) introduced a new regime for fixing the renminbi on August 11th. The second was this winter, when another surge in outflows that coincided with the Fed’s December rate hike made it impossible for the Fed to keep doing so. So, if capital seems happy to stay in China, is it now ‘safe’ for the Fed to tighten US monetary policy?

美联储(Fed)可能从中获得解脱。在过去一年里，美联储的加息意图两次因中国大规模资本外流引起的金融动荡而落空。第一次是去年夏季，当时中国人民银行(PBOC)在8月11日推出新的人民币汇率形成机制，导致资本外流急剧飙升，美联储被迫推迟加息。第二次是去年冬季，在美联储12月加息的同时，中国又一次出现了大规模的资本外流，这让美联储不可能继续加息。因此，如果资本看上去乐意留在中国，那么美联储现在收紧美国货币政策是不是就是“安全”的？

Not quite. Actually, the main reason why capital isn’t flowing from China these days is precisely because of the fact that the Fed hasn’t been expected to raise rates. If that were to change, capital outflows from China would once again become a source of global risk aversion.

未必。实际上，最近资本没有流出中国的主要原因正是外界预期美联储不会加息。如果这种预期发生改变，中国资本外流将会再次引发全球性的风险规避行为。

US monetary policy and the capital account of China’s balance of payments are joined at the hip. To understand why, it is important to look back to the period 2009-2013, when many emerging economies took advantage of very loose US monetary policy and borrowed heavily in dollars. Borrowers in Brazil, Russia, India, Indonesia, Mexico and Turkey all responded to the Fed’s Quantitative Easing by adding relatively cheap dollar liabilities to their balance sheets.

美国货币政策和中国国际收支资本账户的关系极为密切。要明白其中原因，就要回过头来看看2009年至2013年这段时期，当时许多新兴经济体利用美联储异常宽松的货币政策，大举借入美元债务。面对美联储的量化宽松政策，巴西、俄罗斯、印度、印尼、墨西哥和土耳其的借款人全都增加了相对低成本的美元债务。

But the way China borrowed dollars during this period was quite different to the others. While most countries issued dollar bonds with relatively long maturities to institutional investors, the bulk of the dollars that China borrowed during this period came from international banks with rather short maturities.

但中国在此期间借入美元债务的方式与其他国家截然不同。大多数国家是向机构投资者发行期限相对较长的美元债券，但中国在此期间借入的美元债务有大量借自国际银行，而且期限短。

At the end of 2008, China’s external debt to foreign banks was less than $200bn, according to the Bank for International Settlements (BIS) (which almost certainly understates the scale of this borrowing). By early 2014, that stock had risen to over $1tn. Astonishingly, a full 80 per cent of this debt carried original maturities of less than one year. No other emerging economy borrowed so much at such short maturities from banks. To do so would have been a ‘rookie error’: most of these countries knew from their own painful financial histories that sensible borrowing is done by issuing long-dated debt.

国际清算银行(BIS)的数据显示，在2008年底，中国欠境外银行的外债不到2000亿美元（几乎可以肯定，国际清算银行低估了中国的借债规模）。到2014年初，中国欠境外银行的外债升至1万亿美元以上。令人吃惊的是，这些债务中有80%的初始期限不足一年。没有哪个其他新兴经济体向银行借入期限如此短的这么多债务。这是“菜鸟才会犯下的错误”：这些国家大多从自身惨痛的金融历史中明白，发行长期债券才是明智的。

The reason why the Chinese borrowed so many dollars with such short maturities lies in the attractiveness of the ‘carry trade’: Chinese banks and firms could borrow dollars very cheaply, sell them for renminbi and then buy a Wealth Management Product (a deposit-like instrument) yielding, say, 6 per cent. And for most of this period, the renminbi was also appreciating predictably against the dollar. So they were profiting not just from the China-US interest rate differential, but also from the capital gain delivered by ‘shorting’ a weakening dollar.

中国借入这么多短期美元债务的原因是“套利交易”的吸引力：中国的银行和企业可以以极低成本借入美元，然后兑换成人民币买入比如说收益率为6%的理财产品（一种类似存款的工具）。在此期间的大部分时间里，人民币对美元也在如预期那样升值。因此他们的利润不只来自中国和美国的利率差异，而且还来自“做空”弱势美元带来的资本收益。

The accumulation of short-term dollar debt by Chinese borrowers created a feedback loop between US monetary policy and China’s capital account, in the following way.

中国借款者借入的短期美元债务不断积累，通过以下方式在美国货币政策和中国资本账户之间形成了一个反馈回路。

Step one: the Fed is expected to raise rates (or, as in December, actually does). Step two: capital is sucked from China, because tighter US monetary policy both strengthens the dollar and cuts the China-US interest differential, giving Chinese borrowers good reasons to unwind their short-dollar positions. Step three: the ensuing capital outflows from China fuel global risk aversion, adding volatility to international capital markets. Step four: that volatility makes it too dangerous for the Fed to tighten policy.

第一步，美联储预计将会加息（或者就像去年12月那样真的加息了）。第二步，资本从中国流出，因为美国货币政策收紧既让美元升值，又降低了中美利差，这让中国借款者有理由将美元空头头寸平仓。第三步，随后中国资本外流引发全球避险情绪，加大国际资本市场的波动。第四步，这种波动让美联储收紧政策的风险过大。

A circuit-breaker is at work, then: the Fed’s ability to raise rates is hobbled by the market volatility which is created by the impact that US monetary tightening has on capital flows from China.

接着断路器开始工作：美联储加息能力受到市场波动的削弱，而市场波动正是因为美国收紧货币政策对中国资本外流的影响导致的。

Over time, this feedback loop is likely to lose its force, and China’s capital account might stop being a burden on the Fed. But we’re not there yet. At the end of last year, the cross-border debt that China owed to international banks was still over $750bn, according to BIS data.

随着时间的推移，这种反馈回路可能失效，中国资本账户可能不再是美联储的负担。但我们现在还没有到那一刻。国际清算银行的数据显示，在去年年末，中国欠国际银行的跨境债务仍超过7500亿美元。

That means the Fed still has a ‘China problem’: any effort it makes to tighten policy will, once more, activate the feedback loop and suck capital from China with what are now predictable consequences. And since net capital outflows are generally unsupportive of growth, the underlying economic problem that China faces can only be made worse by US monetary tightening.

这意味着，美联储仍面临“中国问题”：其任何收紧货币政策的努力将再次激活这种反馈回路，促使资本流出中国，带来现在可以预料的结果。由于资本净流出通常对经济增长不利，中国面临的基本经济问题只会因美国收紧货币政策而变得更为严峻。