How different is it this time?

A POPULAR phrase that gets bandied about in times of extreme bullishness or bearishness is "it's different this time".

It was employed to good effect during the dotcom boom in 2000 when greedy if bewildered investors were told to keep buying stocks trading at stratospheric prices with no earnings or track records because of the unlimited potential of the Internet, and it made the rounds again in 2008 when the US subprime crisis struck, though at that time, it was used to feed on fear, not greed.

It's a phrase that's now beginning to be heard again to nourish fear - oil has fallen dramatically, China is slowing drastically and depressingly, and there is real worry that central banks, having tried printing their way out of trouble repeatedly over the years and now look to be failing, have exhausted their toolkit and are out of ideas and options.