AUSTRALIA has the second-best quality of life in the world and could pip Norway for top spot, the author of a UN report on migration and development says.

Australia was ranked second among 182 countries on a scale measuring life expectancy, school enrolments and income in the United Nations Development Program's Human Development Report 2009, released yesterday.

The US slipped a spot to 13, while Britain remained steady at 21, based on the most recent internationally comparable data from 2007. Niger ranked lowest, followed by Afghanistan.

In Australia, life expectancy was extended three months and income rose 4 per cent on a year earlier, report author Dr Jeni Klugman said. But the scale does not account for inequality within a country and is not a direct representation of its allure to migrants.

Instead, the human development index ranks countries into tiers of development. Most international migration is contained within those tiers. For instance, less than 1 per cent of Africans have moved to Europe, and just over a third of the world's 200 million international migrants moved from a developing country to a developed one. For the majority, the move is a more subtle one in search of greater opportunity.

''Most migration, internal and international, reap gains in the form of higher incomes, better access to education and health, and improved prospects for their children,'' the report said.

While Australia is largely a migration success story, the toll on Aboriginal and Torres Strait Islanders has been high, Dr Klugman said. ''It clearly had large and unacceptable costs for indigenous people,'' she said.