The buzz words and explanations for the inexplicable might change but nothing in the markets is ever new, so it's just a question of finding the right bear market to see what's going to happen next.

You can rule out 1987 for a start. Back then inflation was rampant (as distinct from today's threatening), corporations went on a debt binge (this time restricted to the banks themselves) and China was still closed. And the 2000 tech wreck was just a bubble bursting.

In its annual report the Bank for International Settlements (BIS), which had been warning about a credit crunch for yonks, suggests we're either going through an early 1970s inflation burst or an early '90s debt overhang.

If it's the '70s again, watch out. As for the early '90s, thankfully the bear market was short-lived despite a recession. Oops, what was that? Don't worry, there was a recession then because interest rates hit 18percent.

So which model did the gnomes of Basle choose? "In the end, both might well prove right." That's central bankers for you, a bet each way, but at least we have a short list. In fact the case for a '90s replay is much stronger than for a bout of the '70s. The reason is we have a fully blown credit crash caused by American banks borrowing too cheaply, because they could, and lending it out indiscriminately. They were lax and are paying the penalty for it, which will be a drawn-out affair.

Talk about deja vu. During the last debt overhang, Westpac and ANZ almost went under. But aren't oil prices worse than in the '70s bear market, one of the deepest and longest ever? Yes, except then it was a contrived shortage of oil; now it's a contrived demand from hedge funds and hoarders. The higher the oil price goes in a speculative frenzy, the faster and further it will drop.

If the market won't do it then sooner or later the central banks will have to take on the hedge funds by pushing up the US dollar which will pull down the oil price. Until then, the markets will be all over the place even if there are good reasons to rule out a global recession.

In the US there's an export boom thanks to the 30percent drop in the US dollar over the past five years, interest rates are low, households have been given a mouth-watering tax cut and the Federal Reserve has shown it won't let any big bank go under.

Which makes this the early '90s all over again, but without a global recession.