As the Reserve Bank of Australia assesses the strength of demand in the lead-up to Christmas and during the holiday period, figures compiled by the Commonwealth Bank show economists tipping a big slowdown in consumer spending in December were on the money.

The CBA's Household Spending Index, which uses transaction data from 7 million bank customers, plunged 3.9 per cent last month to 137 points after jumping 1.6 per cent in November.

The decline occurred across most categories, led by a 16 per cent plummet in expenditure on household goods - more than reversing a 7 per cent rise the previous month - a 6.5 per cent drop in spending on recreation and falls in purchases of food and drinks and on hospitality.

Higher fuel prices helped drive a small 1 per cent increase in spending on transport, while rising insurance premiums and health care charges also pushed up spending on essentials.

Commonwealth Bank senior economist Belinda Allen said the fall confirmed the pattern of recent years where sales helped drive spending up in November before weakening the following month.

The economist said it was clear that consumers were feeling the pinch of high living costs and interest rates, and had brought forward their spending to take advantage of the discounts being offered by retailers during the Black Friday sales period.

"Household budgets are undoubtedly constrained with rate rises leading to a weakening of consumer spending," Ms Allen said.

She said the result, combined with the drop in headline inflation to 4.3 per cent in November, supported the CBA's view that interest rates have peaked and will begin to come down later this year.

The bank is forecasting a relatively rapid easing, including three 0.25 percentage point cuts between September and December, and a further three in the first half of 2025, pushing the official cash rate down to 2.85 per cent.

In further evidence that the economy is slowing, demand for workers was essentially flat last month.

The ANZ-Indeed Australian Job Ads index increased a bare 0.1 per cent in December after a cumulative drop of 8.9 per cent between August and November.

Indeed senior economist Callum Pickering said the index fell by almost 15 per cent last year across most occupations as the economy slowed and the need for workers softened.

But he said job ads for 80 per cent of occupation categories remained above pre-pandemic levels.

ANZ senior economist Catherine Birch said even though conditions in the labour market were easing, "there are no signs of a sharp deterioration approaching".

Ms Birch said the number of vacancies per unemployed person were still double their pre-pandemic level and predicted only a modest lift in the jobless rate this year.