Australia is still the world's happiest nation based on criteria including income, jobs, housing and health, despite some signs of a slowing economy, according to the Organisation for Economic Co-operation and Development.

Australia kept the top spot for the third straight year, leading Sweden and Canada, the Paris-based group's Better Life Index showed, when each of 11 categories surveyed in 36 nations is given equal weight.

Happy times in Australia.

More than 73 per cent of people aged 15 to 64 in Australia have a paid job, above the OECD average of 66 per cent, while life expectancy at birth in Australia is almost 82 years, two years higher than the OECD average, the survey showed.

Australia, the only major developed nation to avoid the 2009 worldwide recession, remains at the top of the OECD index even as the mining boom powering economic growth crests and the government forecasts unemployment will rise to 5.75 per cent by June 2014, from 5.5 per cent last month.