US (BBN)-The gap between the rich and the poor keeps widening, the Organisation for Economic Cooperation and Development (OECD) says.

In its 34 member states, the richest 10% of the population earn 9.6 times the income of the poorest 10%, reports BBC.

There is no standard measure of inequality, but most indicators suggest it slowed or fell during the financial crisis and is now growing again.

The OECD warns that such inequality is a threat to economic growth.

It says this is partly because there is a wider gap in education in the most unequal countries, which leads to a less effective workforce.

OECD member states include most of the European Union as well as developed economies such as the US, Canada, Australia and Japan.

One of the factors that the OECD blames for growing inequality is the growth in what it calls non-standard work, which includes temporary contracts and self-employment.

The OECD says that since the mid-1990s more than half of all job creation in its member states has been in non-standard work.

It says that households dependent on such work have higher poverty rates than other households and that this has led to greater inequality.

It also says that tax and benefit systems have become less effective at redistributing income.

On the other hand it says that one of the factors limiting the growth in inequality has been the increasing number of women working.

The report says that one of the few areas where inequality has not been growing in the last 30 years has been Latin America, although levels of inequality were much higher there to start with.