There is one. Even if today's inflation news is awful (and it almost certainly will be) the Reserve Bank is unlikely to push up interest rates.

In normal circumstances if the inflation number due out this morning was bad, the Reserve Bank board would push up interest rates almost automatically.

Not even an election would stop it, as we discovered late last year.

The bank's trigger for a rate rise is 0.8 per cent. If the quarterly rate of underlying inflation comes in at 0.8 per cent or higher, the RBA takes it as a sign that the annual rate of inflation will soon be above 3 per cent and jacks up rates. If the quarterly rate is 0.7 per cent or below, it leaves rates put. But not this time.

Westpac and the ANZ are predicting a shocker of an inflation result today an underlying inflation rate of 0.9 per cent for the quarter and 3.4 per cent for the year.

But the bank's board won't react as it usually would when it meets on February 5. For two reasons.

One is Australia's big private banks put up their rates independently of the Reserve. It might want to wait and see what happens.

The other is the sharemarket rout changes everything. In an immediate sense it is making well-off Australians poorer, especially those who have borrowed to buy shares. That by itself will take pressure off inflation as they find themselves less able to spray around money.

The rout could bring on a worldwide economic slowdown. Goldman Sachs downgraded yesterday its forecast for Australian growth this year from 3.5 per cent to 3 per cent. It cut its forecast for next year to 2.75 per cent.

Malcolm Turnbull used to run Goldman Sachs in Australia. He is now the Opposition's treasury spokesman. He thinks the rout is already hurting the economy.

As he put it yesterday, "As every day goes by, the case for the Reserve Bank holding its hand and not raising rates becomes stronger." The bank is likely to agree with him and sit on those hands when it next meets, no matter how bad our inflation rate.