Confidence is highest in the U.S. But that doesn’t mean it necessarily should be.

In Australia, only 32 percent of respondents are highly confident in their retirement prospects.

But Aussies save substantially more than Americans, largely due to higher contribution and deferral rates, which are mandated at the federal level.

Average household income for respondents in Australia was $66,000, compared to $107,000 in the U.S, according to the survey.

Yet the average investable assets for respondents down under were $349,000, compared to $247,000 in the U.S.

Australia mandates that employers contribute 9.5 percent of salary to a savings plans, and is currently weighing proposals to move that to 12 percent in the future. Workers there also contribute and average of 7.5 percent to defined contribution plans.

“In the United States, mandatory employer contributions would clearly be at odds with America’s business culture,” according to the report’s authors. While mandated contribution levels were widely unpopular at first, they have become an accepted standard in the Australian benefits landscape.

Australians’ higher saving levels, in spite of making significantly less than Americans, is clear evidence of the effectiveness of higher contribution rates on retirement preparation, according to the report.

In the United Kingdom, where 43 percent of survey respondents expressed high levels of retirement confidence, the government has mandated auto-enrollment in workplace plans for the largest employers in 2012 and has been phasing more employers in since.

Of those automatically enrolled, only 10 percent have opted out overall, according to State Street.

“It’s unlikely that the United States would implement auto-enrollment nationwide,” said the report, even as more states are exploring implementing such requirements for small employers at the state level.

In spite of a general preference for lower government regulation in the U.S., the survey’s authors suggest looking down under and across the pond could be instructive for those plan sponsors with a genuine investment in improving savings outcomes.

Fredrik Axsater, global head of SSGA Defined Contribution, says the “Australian paradox” debunks the presumption that retirement confidence is strictly correlated with higher account balances.

The recent drop in global commodity prices has likely impacted Australians’ confidence levels, as the country is a major commodities exporter, notes the report.

“Both plan sponsors and participants need to consider other factors when assessing confidence, such as culture, the state of the economy, pending legislation, plan design and individual circumstances,” said Axsater in a release.

“It is important that we move away from a singular view of confidence to a broader view of the financial life of people,” he added.