TV ratings giant Nielsen Media Research said something Monday that major broadcasters didn't want to hear: Young men simply are watching less network television.
The search for the missing 18-to 34-year-old male viewers has been one of the most talked-about behind-the-scenes dramas in the TV industry this fall.
Network executives -- protective of the more than $17 billion spent every year by advertisers that buy time based on Nielsen ratings -- have conceded that some of their newest offerings haven't appealed to young men. But the networks also have accused Nielsen of faulty measurements, saying that nothing else explains the sudden and steep audience drop-off for popular shows such as "Friends," "CSI: Miami" and "24."
On Monday, Nielsen disagreed. In a 43-page report, it defended its measurements as accurate.
In fact, the report concluded, the data revealed that men younger than 35 have been watching nearly 6% less television this season. In the key prime-time viewing block, the decline is 7.7%.
The losses, Nielsen said, were nothing new.
"When looking at more long-term trends, we see that prime-time viewing by this demographic group has been declining for some time," Nielsen said.
Executives at ABC, CBS, NBC and Fox Broadcasting Co. declined to comment on the report, saying they needed time to digest its contents.
Broadcast networks and pay cable channels, such as HBO, have suffered the biggest losses, and ad-supported cable channels, such as MTV, have shown gains, Nielsen said.
The findings underscore what some in the industry say is a generational shift, as people now come of age in a world in which the networks represent a fraction of the scores of TV channels and other entertainment options available.
These viewers feel as much at home watching Comedy Central or the Disney Channel as they do tuning in to ABC or CBS -- perhaps more so.
"This is a generation that is more democratic," said Betsy Frank, executive vice president for research for MTV Networks, which has seen an 11% increase this year among viewers 18 to 24. "They don't see differences between broadcast channels and cable channels."
The Nielsen report said the first evidence of the erosion began last spring and accelerated in the fall.
The report said that young men who lived with their parents were watching even less TV this season, particularly in prime time.
That jibes with what industry experts long have known: that younger men tend to watch more TV outside the home and are less likely to record their viewing. Nielsen, for example, doesn't count viewers in sports bars or dorms.
"They're not homebound people, and measuring their viewing patterns is very difficult," David Poltrack, CBS' executive vice president for research, said Friday.
Nielsen, owned by the Dutch publishing giant VNU, attributed much of the declines to the increased popularity of video games and DVDs.
For example, video game usage among men 18 to 24 is up 9% this year.
If the networks continue to lose younger viewers, the repercussions could be far-reaching.
Networks' business models are based on fetching higher ad rates for shows that appeal to younger viewers. And advertisers are grumbling that they are unwilling to pay more each year for network time when these shows have been drawing less of their target audience.
In addition, shows that have been the most popular with the younger crowd -- "reality" shows -- also are the ones that networks have been shying away from.
"By not putting on more reality shows this fall, the networks might have participated in their own downfall," Frank said.
Networks also have placed a premium on prime-time programming, focusing on the 8-to-11-p.m. period. But cable channels have found that younger adults tend to tune in later in the evening. MTV, for example, doesn't begin its marquee programming until 10 p.m.
Experts say the proliferation of DVDs and, to a lesser extent, personal video recorders has allowed some viewers to be more independent in their entertainment selections.
No longer do young adults need to race home by 9 p.m. Tuesdays to see "MASH," said Charles Hirschhorn, founder and chief executive of G4, a Comcast Corp.-owned cable channel devoted to video games.
"TV usage is no longer passive; younger viewers are not doing what they are told," Hirschhorn said. Instead, if they like a program and their friends are talking about it, they will watch it. But if they miss a show, they can watch it later in the year when the DVD is released.
"This is clearly a massive shift in how people are using their televisions," Hirschhorn said. "It's an interesting evolution."
The report was released the same day that the networks touted their November ratings. In conference calls, top network executives acknowledged that young men did not connect with many of the shows introduced this fall.
"Until we put on shows that continue to bring in more viewers, then we're not doing a good enough job," NBC Entertainment President Jeff Zucker said.