Academic salaries are no longer sufficient to attract the brightest and best into the sector, according to the co-author of a new global survey of higher education pay.
Philip Altbach, director of the Center for International Higher Education at Boston College, said that academic pay lagged behind that of many other professionals, with pay gaps most pronounced in senior posts.
His comments preface the publication next month of a report on academic pay in 28 countries, titled Paying the Professoriate, jointly authored by academics at Boston College and the Higher School of Economics in Russia.
The study considered average salaries for academics in full-time permanent posts at public universities worldwide, adjusted to reflect the cost of living in each country. It indicated whether an academic salary was enough to allow scholars to live a "middle-class" lifestyle.
Canada topped the pay league, with academics receiving an average of $7,196 (£4,537) a month before tax, when figures were adjusted for purchasing-power parity.
The UK finished in seventh place - behind Italy, South Africa, India, the US and Saudi Arabia - with academics being paid $5,943 a month on average, just ahead of Australia, the Netherlands and Germany.
The lowest paid were academics in Armenia, who earned about $538 a month - less than a tenth of UK pay. Slightly better off were their peers in Russia ($617) and China ($720). The report noted that moonlighting was rife in these countries.
In many countries, professorial pay was also significantly lower than the salaries awarded to senior figures in a number of professions, said Professor Altbach.
"You can tell the health of a higher education system by whether it can recruit the best and brightest within society" - and in most countries they cannot, he said.
"In low-paid countries, academics get as much moonlighting in a second job as they get for their normal salary. In average-paid countries, most rely on some extra work, which is ultimately bad for the system as they are not fully focused on their main role."
Professor Altbach noted that national variations in salaries contributed to a global brain drain from countries where academics were less well paid.
"Even where academic salaries compare relatively well with general wages, as in India, the much higher base salaries in North America or Europe lure many Indians abroad," he said.
In many countries, universities were competing with law and accountancy firms to attract good staff, he noted, but salaries in those professions had risen so much that the higher education sector was struggling to keep up.
"Even the salaries of law professors, who are paid a third more than other professors, do not compare favourably to someone employed at a half-decent law firm," he said.
"School superintendents will earn much more than the people training them at universities."
However, academics at the very top of their fields did have the potential to command high salaries, Professor Altbach said.
"[Those at] the top of the professoriate are part of a global labour market for academics. Their salaries can be very high, but this is not true for the vast majority."
The data used in the study took into account extracurricular pay, pension payments and other fringe benefits.
The report also highlighted facets of academic pay that were unique to specific countries. Some Indian academics received a bonus for having a vasectomy or hysterectomy, the study said, while Mexican scholars traditionally receive a frozen turkey at Christmas.
Salaries for academic staff at private universities, such as Ivy League institutions in the US, were not considered in the study. But those scholars were not necessarily better paid, noted Professor Altbach. Academics at for-profit institutions in Brazil and China were often on lower rates of pay than those at state universities, he said.
Paul Curran, vice-chancellor of City University London, who chairs the Universities and Colleges Employers Association, which negotiates academic pay, said he believed that comparisons between countries were difficult, but he welcomed the report.
"The UK's academic staff are highly valued and committed professionals with reward packages and contracts that reflect this," Professor Curran said.
But Sally Hunt, general secretary of the University and College Union, said that despite punching above their weight globally, UK academics were paid less than contemporaries in "key comparator countries".