They have fallen steadily since the 1980s and remain close to historic lows. 自上世纪80年代以来，它们一直在稳步下跌，目前仍旧接近历史低点。

And that underpins all sorts of other asset prices. 而且，这支撑起了所有种类的其他资产价格。

A widespread concern is that the Fed and its peers have grossly distorted bond markets and, by extension, the price of all assets. 一种普遍的关切是，美联储及其同行严重地扭曲了债券市场。相应地，也扭曲了所有资产的价格。

Warren Buffett, the most famous disciple of Ben Graham, said this week that stocks would look cheap in three years' time if interest rates were one percentage-point higher,  本周，格林汉姆最著名的信徒沃伦·巴菲特称，如果利率再高一个百分点，股票在3年内期看上去会是便宜的；

but not if they were three percentage points higher. 但是，如果再高3个百分点，就不便宜了。

But if interest rates and bond yields were unjustifiably low, inflation would take off - and puzzlingly it hasn't. 但是，如果利率和债券收益率不合理地处于低位，通胀就会飙升——令人困惑的是，通胀没有飙升。

This suggests that factors beyond the realm of monetary policy have been a bigger cause of low long-term rates. 这表明，某些处于货币政策领域之外的因素是长期利率处于低位的一个更大的原因。

The most important is an increase in the desire to save, as ageing populations set aside a larger share of income for retirement. 最重要的是储蓄愿望的上升，这是因为老龄化人口把退休收入中的更大的一部分留了出来。

Just as the supply of saving has risen, demand for it has fallen. 就在储蓄的供给增加了的同时，对储蓄的需求却下降了。

Stagnant wages and the lower price of investment goods mean companies are flush with cash. 停滞的工资以及投资商品的较低价格意味着各家公司都是现金充裕。

All this suggests that interest rates will stay low by historical standards. 这一切表明，以历史标准连连看，利率将处于低位。

Still the most dangerous, anti-Graham motto of investing is “this time is different”. 然而，最危险的反格林汉姆的投资格言是“这次不一样”。

It would be daft to assume that asset prices must remain high come what may. 认为不论如何资产价格必须维持在高位会是愚蠢的。

Many hazards could derail the economy and financial markets, from a debt crisis in China to an American-led trade war or an outbreak of fighting on the Korean peninsula. 诸多风险——从中国的债务危机到美国发起的贸易战争，抑或是朝鲜半岛战事爆发——都可能让经济体和金融市场出轨。

And when the next recession comes, policymakers have less fiscal and monetary ammunition to fight it than they had in previous downturns. 而且，当下次危机来临时，决策者比他们在前几次衰退中少了一些财政和货币弹药来抗击衰退。

Prudence therefore suggests caution. 因而，谨慎意味着避免可能的风险。