LONDON, September 9, 2008 (AFP) - The OECD called on its member countries Tuesday to better resource their universities or risk polarising their societies between those who can afford higher education and those who cannot.

In its annual report on education, the Organisation for Economic Cooperation and Development noted that while per-student expenditure at the primary and secondary levels rose from 1995-2005, several OECD countries failed to increase tertiary education spending in line with increases in student numbers.

The 30-country Paris-based grouping warned, however, that simply ploughing money into higher education would not be sufficient, and noted that investments would have to become more efficient, as well.

'While nobody can predict how far the expansion in tertiary education will continue, countries need sustainable financing systems capable of responding to growing student numbers,' the OECD said.

'Not doing so could mean that the knowledge society could be a polarised world, peopled by those who can afford education and those who cannot.'

According to the report, spending per student at the primary and secondary level 'considerably increased' on average between 1995 and 2005, and the overall student population aged 5-14 years old is set to decline in 23 OECD countries in the coming decade, thereby freeing up greater resources.

It notes, however, that 'the pattern is different at the tertiary level.'

While the proportion of students in OECD countries going to university rose to 57 percent in 2005 from 37 percent in 1995, 'spending per tertiary student shrank in some cases, as expenditure failed to keep up with expanding student numbers.'

'It appears that without additional investments, the tendency towards declining ... expenditure (per student) could even accelerate,' it said.

To cope with rising student numbers, OECD countries have generally taken one of three policy routes -- either they have ramped up public expenditure on higher education, increased up-front costs for students, or maintained the status quo.

Nordic countries have thus far chosen the first of those options, whereas several other countries such as the United States, Japan and Britain have shifted some of the costs to students and their families while also providing a combination of loans and scholarships to help the less well-off.

The OECD warned, however, that several European countries had not increased government spending on tertiary institutions while not allowing them to charge students for university, thereby putting budgetary pressures on the universities.

It noted that per-student expenditure at university level in most European countries is 'well below half' that in the United States.

'While choices between greater public investments and a larger share of private money are difficult to make, doing neither in the face of the rising demand for more and better tertiary education seems no longer an option,' the report said.

It said that a major challenge for rich countries would be to deploy increased resources in higher education, possibly with some degree of private funding, while not compromising on equity.