港 金融管理局（Hong Kong Monetary Authority，简称：金管局）和中国央行7月19日在港签署了两份具有里程碑意义的合作备忘录，双方就扩大人民币贸易结算安排及在港银行人民币业务 的清算达成共识。上述备忘录的签署是否标志着人民币离岸市场的真正形成？迄今为止，人民币离岸市场的发展主要受到两方面的限制：一是中国内地针对资本流动 甚为严格的外汇管制；二是人民币的有限兑换制度。
要想回答这个问题，首先要了解中央政府希望实现的目标以及希望规避的风险。政策制定者显 然也明白，中国经济的长期发展将取决于人民币的国际化，即在全球范围内，人民币都可用作交易结算的货币。要想实现这个目标，需要放松资本的管制。目前，要 想在中国境外使用人民币进行贸易结算还是很困难的。同时，大量不受监管的离岸人民币市场纷纷涌现，中央政府也希望能够遏止这一现象。
1963 年7月，美国开征15％的利息平衡税，有效地控制了资本外流的现象，却也促成了欧洲和亚洲离岸美元市场的形成。自那以后，关于离岸货币市场的研究就层出不 穷。利息平衡税的开征本想将更多的美元留在美国境内，不想却促成了如今为人熟知的以伦敦为中心的“欧洲美元市场”（在欧洲经营美元存款交易的国际资金借贷 市场）的快速发展，堪称一个典型的事与愿违的案例。异军突起的离岸金融中心伦敦无疑是香港的金融监管层试图仿效的对象（尽管直到1979年，前首相撒切尔 夫人才废除了针对英镑的外汇管制）。
出于几种原因的考虑，此类离岸市场也可能是一把双刃剑，理由如下：
首 先，在离岸货币市场提供外汇存贷业务的银行没有义务遵循在岸市场存款准备金比率的相关要求。当然，这些银行也就无法获得央行对在岸市场的流动性支持和贴现 窗，服务。这一方面给离岸银行提供了更大的空间以拓展他们的美元产品。但同时也意味着，一旦遇到流动性紧缩的状况，上述银行将面临更大的风险。
其 次，同一家银行，在离岸市场运营时，并不需要像在境内市场一样遵循资本充足率的相关规定。多年来，欧洲银行并无义务为手中持有的美元资产或债务准备大量资 本金。对银行来说，这也是一个利好，但同时也蕴含了更大的风险。从上世纪80年代开始实施的《巴塞尔协议》通过对整体资本充足率做出规定，在一定程度上解 决了这个问题口但是这个制度还是不尽完善。
再次，如果某一资产以监管者所在国货币计价，但却在境外持有，那么对于监管层来说，想要为此类资产设定流动性要求，一般来说是不可能的。以欧洲美元市场为例口离岸银行在美国境内持有美元存款，尽管此类资金并不由央行提供，他们仍可将之视为准备金。
从 这个角度看，我们就不难理解中央政府为何对设立离岸人民币市场相当谨慎。离岸货币市场为金融、法律、会计及其它机构创造了大量的机会。但是从货币发行和监 管的角度来看，此类市场并不稳固。从本质上讲，离岸货币市场的运作同影子银行或平行银行体系类似，上面分析的三点对这三种系统均适用。
此类系统往往在经济上升周期迅速扩张，而在经济衰退时急剧收缩。如果监管不当口离岸货币市场和影子银行系统就好比“杠杆化”的基础货币制度口会双向放大经济周期的波动效应。
近 来美国影子银行体系的扩张和收缩恰恰说明了这一点。2003年的时候，美国影子银行的负债只有8万亿美元，但是到了2008年雷曼兄弟（Lehman Brothers）破产前夕，这个数字已经激增到14.8万亿，增幅为85%。同期美国官方银行的负债从5.8万亿美元增加到了7.6万亿口增幅只有 30%。这里我们所说的影子银行体系是由投资银行、货币市场基金、信贷公司以及提供杠杆流动资金的机构（他们通过诸如抵押贷款支持证券等金融工具构成的交 易市场提供服务）组成的网络。
然而，随着雷曼兄弟在2008年9月破产，美国影子银行体系骤然崩溃口负债从彼时的14.8万亿美元迅速收 缩至2010年3月的11.7万亿美元口降幅高达20%。相比之下，尽管在2008年9月之后，由于情绪激动的投资人将大量资金从货币市场基金和资本市场 中撤出，并将这些海量资金转入银行，而美联储也向银行投放了大量货币，美国官方银行体系的负债在短期内曾出现激增，但过去一年里官方的货币供应还是稳定在 了8.5万亿美元的水平。
而对于一直试图控制国内人民币供应的中央政府来说，这一点尤其需要顾虑。在现代银行体系中，货币（大部分是存款 负债）是由净信贷投放创造的。因此，对于离岸人民币市场来说，其未来的发展前景在很大程度上取决于提供人民币存款业务的银行是否被允许提供人民币贷款业 务，以及此类银行适用何种流动性和资本充足率的规定。中央政府对于这一点的担忧并未完全解除，这一点从此次签署的协议中就可以看出，协议中有一项条款规 定，香港本地金融机构禁止向个人客户提供人民币贷款业务。现在香港的银行可以向企业客户发放贷款，前提是贷款的资金来自贸易交易。
此外， 金管局也明智地对流动性做出了要求，规定香港本地银行的人民币现金及在中国银行香港支行的结算账户余额的总额需保持在“不低于客户存款的25%”的水平。 而中银香港会将这笔资金存放在中国境内的银行同业拆借市场，这又限制了离岸市场的发展。中国央行和其它监管机构能够借此继续控制资金来源的渠道，有效地控 制了贸易结算中使用的人民币数量。
此举将催生出更加国际化的人民币，不过是以规避中央政府某些最深切顾虑的方式实现的。如果7月19日签 署的两份备忘录能够令中国境外的银行自由地为有投资和纯粹融资需求的客户提供人民币贷款，那么内地监管机构为了保护境内人民币市场的完整和控制力而竖起的 “长城”将会被摧毁，那些“野蛮人”也因此能够在国门外制造麻烦。眼下，这些担心似乎还很遥远口而在目前的管制下，离岸人民币市场的发展也仍然是有限度 的。
The Hong Kong Monetary Authority and the People's Bank of China signed two landmark memoranda on July 19 agreeing to expand yuan trade settlement and clearing in Hong Kong. Could these agreements potentially mark the start of a genuine offshore market in yuan, one that has hitherto been suppressed by the mainland's tight foreign-exchange controls on capital movements and by limited convertibility?
To answer that question, it's important first to understand what Beijing hopes to accomplish and what it hopes to avoid. Policy makers appear to understand that China's long-term economic development will hinge on having an international currency that can be used to settle transactions around the world. This requires easing capital controls that currently make it hard for businesses to use yuan anywhere but in China. At the same time, authorities are keen to avoid largely unregulated markets for yuan springing up offshore.
Offshore currency markets have been widely studied since the creation of the offshore U.S. dollar market in Europe and subsequently in Asia, following the imposition in July 1963 of the 15% U.S. interest-equalization tax, effectively a tax on capital outflows. In a classic case of the law of unintended consequences, legislation designed to keep more money onshore instead led to the rapid development of what generally became known as the euro-dollar market (i.e. the market for dollars in Europe) centered in London. The extraordinary rise of London as an offshore financial center -- despite exchange controls on sterling until Margaret Thatcher abolished them in 1979 -- is no doubt something Hong Kong regulators would seek to emulate.
But such offshore markets can be a double-edged sword, for several reasons.
First, banks offering foreign-currency deposits and loans within an offshore currency area have no obligation to observe reserve-requirement ratios that operate in the onshore currency area. By the same token, these banks do not have access to the central bank's onshore liquidity back-up or discount-window facilities. That gives offshore banks greater latitude to expand their dollar offerings. But it also means greater risk in the event of a liquidity squeeze.
Second, banks participating in an offshore market were free from the capital-adequacy requirements imposed on them in the currency's home market. For many years, European banks were not obliged to hold capital against their dollar assets or obligations. This again can be a boon for the banks, but entails greater risk. Basel capital regulations, starting in the 1980s, have partly addressed this problem by focusing on a bank's overall capital-adequacy ratio, but this regulatory framework remains imperfect.
Third, it's generally not possible for regulators to impose liquidity requirements on assets denominated in the regulator's currency but held offshore. In the euro-dollar case, offshore banks held dollar deposits at onshore U.S. banks, treating these as reserves even though they were not supplied by the central bank.
Viewed in this light, it's easy to understand Beijing's caution about the development of an offshore yuan market. Offshore currency markets create a myriad of opportunities for a range of financial, legal, accounting and other firms. But they are unsound in a monetary and regulatory sense. Offshore currency markets operate essentially in the same way as shadow or parallel banking systems, with which they share the three common elements outlined above.
Typically such systems experience faster expansions during business-cycle upswings and more abrupt contractions during recessions. If not properly regulated, offshore currency markets and shadow banking systems operate as leveraged versions of the underlying currency systems, amplifying fluctuations in both directions.
For example, in the recent expansion and contraction of the U.S. shadow banking system -- meaning the web of investment banks, money-market funds, finance companies and the like that provided leveraged liquidity via markets for instruments like mortgage-backed securities -- shadow banks' liabilities grew to $14.8 trillion in 2008 right before the Lehman Brothers collapse from $8 trillion in 2003, an 85% increase, while the official banking system's monetary liabilities grew to $7.6 trillion from $5.8 trillion, or just 30%.
Conversely when the shadow banking system imploded following the bankruptcy of Lehman Brothers in September 2008, their liabilities contracted abruptly to $11.7 trillion by March 2010 from $14.8 trillion, or by 20%. By contrast, following an initial surge after September 2008 as skittish investors flooded dollars into the banking system from money-market funds and the capital markets and the Federal Reserve pumped money into the banks, the official money supply has been virtually static around $8.5 trillion for the past year.
This will be a particular concern to Beijing, which already struggles to control the supply of yuan domestically. In modern banking systems, money (which is largely deposit liabilities) is created by net new lending. The future growth prospects of the offshore yuan market depend on whether banks that offer yuan deposit facilities will also be allowed to lend in yuan, and what liquidity and capital requirements will apply. Beijing's concerns on this front have not entirely eased, as evidenced by a provision in the new agreement specifically prohibiting yuan lending by Hong Kong institutions to personal customers. Banks in Hong Kong can now lend funds received from trade transactions to any corporate customer.
Moreover, the Hong Kong Monetary Authority has wisely extended a liquidity requirement instructing banks in Hong Kong to maintain yuan cash-plus-settlement balances at the Bank of China (HK) 'at no less than 25% of customer deposits.' Bank of China (HK) in turn will place these funds back in China's onshore interbank markets, again limiting the growth of the offshore market. The Chinese central bank and other regulators therefore continue to limit access to funding sources -- effectively the volume of yuan used in trade settlement.
The net result is a more international yuan, but in a way that avoids some of Beijing's most serious concerns. If as a result of the July 19 memoranda banks outside the mainland had been able to lend freely in yuan for investment and purely financial purposes, then the Great Wall preserving the integrity and control of the onshore yuan by mainland regulators would have been breached and the barbarians would have been able to make trouble outside the gates. For the present those concerns can be postponed, but correspondingly the growth of the offshore yuan market will also remain limited under current constraints.