France has a reputation for its good quality of life

Mr Sarkozy said he had asked ex-World Bank chief economist Joseph Stiglitz to lead a taskforce along with Indian economist Armatya Sen as an advisor.

Mr Sarkozy said the new measure should address quality-of-life issues, not simply Gross Domestic Product (GDP).

Analysts have said France needs to embark on reforms to boost growth.

"We must change the way we measure economic growth," Mr Sarkozy told reporters.

Economic reforms

Mr Sarkozy, who came to power in 2007, said he was keen to boost France's economy by increasing productivity through longer working hours.

Back in 2006, a report from the International Monetary Fund (IMF) commissioned by Mr Sarkozy - then finance minister - said France could significantly boost its economy but would have to undergo serious labour reforms.

The report said the biggest barrier for France was how to convince the public of the benefits of a far more flexible labour market and of other reforms in services and product markets.

Mr Sarkozy's attempt to reform labour laws to date has met strong opposition.

And he is expected to face further difficulty over his plans to reform the state pension system.