Westpac's chief economist Bill Evans welcomed the result, highlighting surges in some of the key sub-indices which make up the headline reading. For example, the index tracking expectations for the economy over the next 12 months rose 5.8 per cent, while that looking at expectations for economic conditions over the next five years soared 24.2 per cent to its highest level since September 2013. The sub-index tracking views on whether now is the time to buy a major household item lifted 4.8 per cent, although it is still 2.2 per cent below its level this time last year. Mr Evans attributed the new-found optimism to Malcolm Turnbull's replacement of doom-monger Tony Abbott as prime minister. The Index is now 8.3 per cent higher than in September, immediately before the leadership change. "It is likely that a boost in confidence towards the economic credentials of the new leadership team played an important hand here," Mr Evans said.

However, Wednesday's results fly in the face of Tuesday's National Australia Bank's latest business sentiment survey, which suggested the Turnbull effect had proved short-lived. Capital Economics' chief economist for Australia Paul Dales ascribed the jump in sentiment to a rebound in the local stock market in September, another drop in petrol prices and the resilience of the jobs market. "It will probably be suggested that confidence is still being boosted by the recent change in prime minister," he said. "However, since the NAB measure of business confidence fell back in October, we think the rise is being driven by other factors."

Westpac's Bill Evans, meanwhile, said there was "another encouraging sign for the Christmas spending outlook" in the result of the bank's special Yuletide question about whether respondents expected to spend "more, less, or about the same" on Christmas gifts compared with last year. "Since we started this question, seven years ago, the average proportion proclaiming 'more' has been 12.5 per cent, " Mr Evans said. "[Wednesday's] survey scored 16.9 per cent, whereas 'less' registered 29.6 per cent, compared to the average of 34.7 per cent," he said. "Consumers in NSW were particularly upbeat, with more planning to increase [rather] than cut Christmas spending compared to a year ago." The main dark spot in the upbeat survey results is people's perceptions of their family finances compared with a year ago, which dropped 2.2 per cent, and expectations for the next 12 months, which plunged 9.1 per cent. Mr Evans said these results – which contrast with broader views about where the economy is headed – could reflect the higher mortgage rates recently announced by the main lenders.

"The assessments of personal finances were presumably linked to the interest rate increases whereas the outlook for the economy was most likely boosted by confidence in the new leadership," he said. US investment bank JP Morgan agreed shoppers had been buoyed by Mr Turnbull's takeover of the prime ministership. Economist Tom Kennedy said "retailers should be somewhat heartened by [the] release". However, he added: "Consumer confidence has not done well as a forecast input for household consumption, but it is nevertheless comforting that the tightening in mortgage conditions is not visibly affecting confidence or spending intentions."