Australia ranked 'happiest' developed nation again

Australia has been ranked the world's happiest nation among developed economies for the third year running.

Top position went to Australia, because of the overall strength of its economy, in the Better Life Index compiled by the Organisation for Economic Co-operation and Development.

Sweden, Canada, Norway and Switzerland were also in the top five.

The survey ranked more than 30 countries on criteria such as income levels, health, safety and housing.

"Australia performs exceptionally well in measures of wellbeing, as shown by the fact that it ranks among the top countries in a large number of topics in the Better Life Index," the OECD said on its website.

More than 73% of Australia's 23 million people aged 15 to 64 have a paid job, above the OECD average.

Life expectancy is also higher, at almost 82 years.

Australia's economy has had more than two decades of growth due to demand for its natural resources.

The nation also managed to sidestep the worst of the financial crisis and was the only major developed nation to avoid the global recession in 2009.

The country's economic strength has been reflected in the Australian dollar, currently trading close to 30-year highs.

However, the government is starting to see challenges to growth as the mining boom tapers off, including rising unemployment.

As a result, the Labor government is now looking to move the economy away from its dependence on mining towards sectors such as construction and manufacturing.

Australia is also facing a widening income gap. According to the OECD, the top 20% of the country's population earn six times more than the bottom 20%.