The study, "The State of the American News Media," was produced by the Project for Excellence in Journalism, a research institute affiliated with the Columbia University Graduate School of Journalism and funded by the Pew Charitable Trusts.
Newspapers today have about 2,200 fewer full-time professional newsroom employees than in 1990, the survey said.
Since the 1980s, the number of network news correspondents has been cut by one-third, while correspondents' workload has increased by 30 percent, it said.
In local television, the average workload increased 20 percent from 1998 to 2002. About 59 percent of news directors reported either budget cuts or staff cuts in 2002.
From 1994 through 2001, the number of full-time radio newsroom employees declined 44 percent and part-time employees declined 71 percent.
In cable, the survey said that only Fox appears to be building its news staff.
And for news magazines, over the last 20 years, Time has reduced its staff by 15 percent and Newsweek by 50 percent.