Economies with a high proportion of healthy, older workers do better and there is little difference between the productivity of older and younger employees, according to a new book.

The book, released at the World Economic Forum in Davos over the weekend, calls for a rethink of business practices to ensure older workers' knowledge and experience is optimized rather than assuming a young workforce is more productive.

Economies not only receive a "longevity dividend" by keeping their over-50s in jobs -- they also increase consumption and tax receipts and reduce welfare spending, and their per capita productivity can also improve, the book, "Global Population Aging: Peril or Promise," claims.

Co-author Simon Biggs, professor of gerontology and social policy at Australia's Melbourne University, said Australian policymakers had started to recognize the need to better engage older workers, but in practice age was still a negative when assessing people for jobs.

"Internationally, there is more recognition of their value in the sense that there's growing competition for their services, whereas Australia still has, for example, these archaic migration regulations restricting over-45s coming here to work," Biggs said.

Australian Employment Participation Minister Kate Ellis said the unemployment rate for mature-age workers was lower than the nation's average of 5.2 per cent at 3.3 per cent.

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