nyse_2142546bCombined tightening by the United States and China has done its worst. Global liquidity is evaporating. What looked liked a gentle tap on the brakes by the two monetary superpowers has proved too much for a fragile world economy, still locked in “secular stagnation”. The latest investor survey by Bank of America shows that fund managers no longer believe the European Central Bank will step into the breach with quantitative easing of its own, at least on a worthwhile scale. Markets are suddenly prey to the disturbing thought that the five-and-a-half year expansion since the Lehman crisis may already be over, before Europe has regained its prior level of output. That is the chief reason why the price of Brent crude has crashed by 25pc since June. It is why yields on 10-year US Treasuries have fallen to 1.96pc, and why German Bunds are pricing in perma-slump at historic lows of 0.81pc this week. We will find out soon whether or not this a replay of 1937 when the authorities drained stimulus too early, and set off the second leg of the Great Depression. More