WASHINGTON — Americans are not as sleep-deprived as they think they are, and in fact appear to be getting more Z’s these days than they got a few years ago, according to an independent analysis of government statistics.

The new findings run counter to the widespread public perception that Americans are getting less and less sleep because of increasing workplace demands and the plethora of distractions available 24/7 on the Internet and cable television.

“Many Americans work too much, but most do not seem to be cutting corners on their sleep to do so,” said John Robinson, a sociologist at the University of Maryland, who led the analysis with faculty colleague Steven Martin. Their report, “Not so Deprived: Sleep in America, 1965-2005,” scheduled for release by the university today, finds that Americans on average got 59 hours of sleep a week in 2005, the latest year for which precise statistics are available. That is three hours more than in 2000.

The new numbers contrast significantly with the 2008 “Sleep in America” poll, the oft-quoted survey conducted annually by the Washington-based National Sleep Foundation, which advocates for better diagnosis and treatment of sleep problems. Released last week, that survey concluded that Americans get an average of only 48 hours of sleep a week.

The difference, experts said, reflects the two groups’ methodologies. The Sleep Foundation survey asks Americans to estimate how much sleep they typically get. By contrast, the Maryland analysis draws upon detailed “time-use” data collected by the U.S. Census Bureau for the Department of Labor Statistics. In that approach, individuals must account for every minute of the previous day.

“This gives us a much better picture of where the time goes than when people just make an estimate,” Mr. Robinson said.

The primary factor affecting the amount of sleep a person gets is whether or not they are employed, the new analysis shows. Apparent differences among men and women and people of varying ages and races effectively disappear when individuals’ employment status is taken into account.

“Older people sleep more, but that’s because they tend to be unemployed,” Mr. Robinson said. If you control for those differences, the differences in sleep disappear too.”

The new data show Americans getting an average of 8.5 hours a night in 2005, compared with 8 hours in 2000.

Addressing the contrast with the National Sleep Foundation data, Mr. Robinson said he is not surprised that people who are asked to simply estimate how much sleep they get tend to underestimate. “It’s a status symbol,” he said. “If you are good American you work all hours. It’s virtuous in American society to not get enough sleep.”