One issue crying out for more attention as part of the accord process is student loans. My new paper looks at how unfair student loans - the largest of which are HECS-HELP loans - have become for women. And how for some, repayment arrangements are unreasonable.

HECS was introduced in 1989 to fund the expansion of higher education in a fair and equitable way. Students who benefited from their education by earning average or higher incomes were expected to contribute to the cost, primarily by making repayments after finishing their studies.

Since then full fee-paying courses, along with student loans to pay these fees, have been introduced. There are also loans for some vocational education and training courses and to help students with other living and study costs.

For courses with government subsidies, the expected contribution has increased from around 20 per cent to 48 per cent of costs. The federal government now lends $7.5 billion to tertiary students each year, with over $6.5 billion going to higher education institutions. In 2021-22, the government recouped more than $5 billion in repayments.

Since HECS was introduced, there has never been a thorough evaluation of Australia's student loan schemes to see how well they are meeting the objective of providing revenue for tertiary education in a fair and equitable way.

My paper shows the growth in higher education over the last three decades, combined with the expansion of student loan schemes and the tightening of repayment arrangements, has resulted in a system that produces negative impacts.

The arrangements are contributing to women's economic disadvantage and are inequitable.

When HECS came in, only 12 per cent of Australians aged 25-34 years had a bachelor degree or higher. By 2021, this figure had grown to 39 per cent. A further 32 per cent had vocational qualifications. This means wage levels for university graduates today are more typical of the general workforce than they were in 1989.

Women are now more likely to obtain a higher education qualification than a vocational qualification. Many occupations traditionally held by women have moved to require professional education and training in the higher education sector, including nursing and other caring professions.

Men's education and training is more evenly distributed between the higher education and vocational education systems (which includes TAFEs). And men earn more, regardless of the sector from which they get their qualification.

The 2021 census shows 54 per cent of men aged 25-40 years with a certificate III to advanced diploma have an income of $65,000 or more. Only 51 per cent of women aged 25-40 years with a bachelor degree or above have an income above this level.

At the same time, it costs a lot more to study at university. Students now finish their degrees with average debts between $50,000 and $60,000.

Former students are taking around 12 years to repay their debts and repayment times are trending upward.

This means former students are repaying debts well into their 30s. By this time, many are having children and trying to buy a house. It is no longer reasonable to think student loans can be repaid before these major life events occur.

Many female-dominated occupations like teaching and nursing employ large numbers of people. Some have high salaries, but a substantial proportion are on modest incomes - particularly women working part-time and balancing family responsibilities. This means many women in these fields end up taking a long time to repay their HECS-HELP debt, or do not pay it at all.

In 2019-20, the greatest amounts of student loan repayments were from female registered nurses ($168 million), followed by female infant and primary school teachers ($130 million).

While there is a large level of debt held by people in these occupations, this is not the case for the many occupations traditionally held by men which require vocational training with comparable levels of income.

In 2019-20, the average taxable incomes of electricians, machinists, and air conditioning and refrigeration mechanics were all over $80,000. This compares to the average taxable incomes of child carers, nurses and primary school teachers which ranged from $38,000 to $70,000. Secondary teachers had average taxable incomes of $78,000.

People only begin repaying their student loan debt once they earn more than a certain amount of income.

From 2019-20, the first threshold was lowered and repayment rates were changed. This required those with incomes between around $46,000 and $60,000 to make repayments.

The changes had most impact on women. Just under two-thirds of those who now had to make a repayment were women (239,000 of 371,000 in 2019-20). Women then paid more than two thirds of the additional revenue from the threshold reduction ($288 million of $429 million in 2019-20).

The new HELP repayment arrangements also reduce the incentive to work and can create poverty traps for some families. For example, for incomes between $48,000 and $100,000, a single parent with two children will lose on average 70 cents of every extra earned dollar due to reduced family benefits and increased tax, Medicare and student loan payments.

In these cases, the HELP repayment arrangements are punitive and undesirable. They are more likely to adversely affect women as they do more caring within families.

The option of reducing student contributions and increasing government subsidies is not likely to occur in the current economic environment. Making tertiary education free or extra cheap for some people makes it more expensive and less equitable for others. This is because the overall objective is to raise revenue to fund the tertiary education system, including universities and vocational education and training.

Instead, the government should make sure that everyone who benefits significantly from the system is a potential contributor and that repayment arrangements are designed to take people's different circumstances into account.

Repayment arrangements should complement other social programs and taxation arrangements. It doesn't make much sense for the government to be providing a low income family with income support while at the same time asserting that one of the adults in that family is so well off, they should be paying for their past education.

HECS-HELP repayments are currently calculated as a percentage of a person's total income, with 18 different thresholds and repayment rates. A single rate of repayment applied to income above a threshold would be simpler and more rational than current arrangements.

It would allow the threshold to be varied according to a person's family circumstances, ensuring former students only make repayments when they really have the capacity to do so.