Australian students working overseas collectively owe the Federal Government more than $6 billion in unpaid loans for their tuition fees, a new report by the Grattan Institute has found. The report is called Mapping Australian higher education, 2013.

As the cost of unversity courses rises, the proportion of the debt that is unlikely to be repaid will increase. The major reason for the shortfall is that a number of debtors are forecast to die or move overseas.

Tertiary education is valuable to graduates, the report found. Male graduates earn 50% more over their careers than men who finished school at year 12, after taking out the costs of education and tax. Female graduates have a 60% net earnings premium.

Taxpayers already foot the bill for the low interest rates charged to students and the cost of the money to the government. The difference is estimated in 2011-12 to be $580 million.