全球股市底气何在？

全球股市底气何在？欧元区处于危机之中，中国正在收紧政策以反击通胀，针对美联储(Federal Reserve)的批评使货币政策走向面临不确定。但全球股市在10月份上涨近20%后，目前仅较11月高点小幅回落。股市为什么表现得这么有韧性呢？

首先，据国际货币基金组织(IMF)预测，全球经济有望今年增长4.8%，2011年增长4.2%。这样的增速或许慢于危机前不久超过5%的速度，但高于1980年以来的平均水平。就连欧元区的危机也没有中断增长：以德国为例，其统一后最快的经济扩张将会给整个欧元区的GDP起到推动作用。

其次，相比昂贵的核心国家政府债券和投资级公司债券，股票显得便宜。据摩根士丹利(Morgan Stanley)估计，2011年欧洲股市的股息收益率为3.8%，而债券收益率为3.4%。前者是后者的1.1倍，远高于90年平均值0.75倍。因此可能还有更多资金流入股市，即使按花旗集团(Citigroup)估计股市相对于2011年预期利润的市盈率是12倍，从基本面来看显得并不便宜。

第三，很多国家超宽松的货币政策可能造成通货膨胀，这将有利于股市而不利于债市。美联储的量化宽松计划将继续向风险资产注资，加息还很遥远。

风险当然是有的。公司已经大幅削减成本，利润率进一步扩大潜力有限。据瑞士银行(UBS)计算，美国公司利润的GDP占比已经接近危机前峰值。与此同时，过去股市投资者对信贷市场问题的反应不够迅速。一些人担心，要是有新的问题出现，政策制定者或许已经没有足够的火力加以应对。

但考虑到公司扎实的资产负债表、稳健的利润，以及经济复苏可能持续（排除欧元区崩盘），哪怕复苏道路并不平坦，股市的走势应该会得到维持。

The euro zone is in crisis. China is tightening policy to combat inflation. Criticism of the U.S. Federal Reserve is creating uncertainty over the direction of monetary policy. Yet global stock markets fell only modestly from their highs in November, after a rally of close to 20% in preceding months. Why are equities proving so resilient?

First, the global economy is likely to have grown 4.8% this year and is forecast to grow 4.2% in 2011, according to the IMF. That may be slower than the 5%-plus rates seen immediately prior to the crisis, but it is above the average since 1980. Even the euro-zone crisis isn't derailing growth: witness Germany, where the fastest economic expansion since reunification will drive euro-zone GDP.

Second, stocks look cheap relative to expensive core government and investment-grade corporate bonds. European stocks offer a 2011 dividend yield of 3.8% versus a bond yield of 3.4%, Morgan Stanley notes; the ratio between the two yields of 1.1 times is far above the 90-year average of 0.75. As a result, further funds are likely to flow into equities even if, trading on a multiple of 12 times 2011 earnings based on Citigroup estimates, they don't look cheap on fundamental grounds.

Third, extraordinarily loose monetary policy in many countries risks creating inflation, which would favour equities over bonds. The Fed's quantitative-easing program will continue to inject liquidity into risk assets; rate hikes are a distant prospect.

True, there are risks. Firms have already cut costs dramatically, so there may be limited potential for further margin expansion. U.S. profits as a share of GDP are close to their pre-crisis peak already, according to UBS. Meanwhile, equity investors have shown themselves in the past to be slow to react to problems in the credit markets. Some fear policymakers are running short of ammunition to deal with any fresh problems that emerge.

But given strong corporate balance sheets, healthy profits and - barring a euro-zone meltdown - a likely continued, if bumpy, recovery, stocks should maintain their poise.