By Caroline Hawley
BBC correspondent in Baghdad
The Iraqi government says it is going to double the salaries of university professors as part of a bid to stem the brain drain in the country.
Doctors say they are struggling with staff shortages
Doctors, teachers and businessmen have left Iraq because they feel unsafe.
No exact figures are available and a government spokesman said there was little in reality that could be done to solve the problem.
Under Saddam Hussein around 4m people are thought to have left, among them some of Iraq's top professionals.
Just after the war, some exiles did return, but more than two years on the country's brain drain, far from being reversed, is continuing at a rate that is alarming many Iraqis.
University teachers will now see their salaries doubled to try to keep them in the country, however the problem is not confined to the campus.
Doctors are fleeing, too, with worrying consequences for a health service already struggling with shortages of equipment and with the number of casualties they are treating.
A junior radiologist told the BBC that many of her senior colleagues had left Iraq because of kidnappings and death threats.
"Most of them have fled out of the country and we are in desperate needs for their expertise.
"This is the main problem that we're facing now in hospital. Most of the senior doctors have fled the country and I believe not only the doctors, all the expertise."
And while doctors have been threatened and kidnapped, dozens of university teachers have also been killed.
A senior government official said he believed Iraqi professionals were being deliberately and systematically targeted.