Ratings have fallen precipitously. In 1988, the top series -- "The Cosby Show," on NBC and "Roseanne" on ABC -- were seen by about 25% of the U.S. homes with TVs. These days, TV's biggest shows, "CSI: Crime Scene Investigation" on CBS and "Grey's Anatomy" on ABC, are on in about 13% of households.
The five networks are owned by conglomerates that also control a lot of the production: Walt Disney Co., News Corp., CBS Corp., Time Warner Inc. and NBC Universal, which is part of the industrial giant General Electric Co. Most of these companies are not heavily reliant on the networks to buttress their bottom lines and therefore could weather a strike better this time.
The lone exception is CBS, which nearly two years ago was separated from its sister company, Viacom Inc. CBS is made up of radio properties, a billboard division, Showtime cable channel and Simon & Schuster publishing, but the broadcast network is the heart of the company. CBS relies on advertising for most of its revenue.
"As CBS' central asset is its television network and production studio, a strike would have a disproportionately negative effect on the company," according to a recent Lehman Bros. research report.
Last week, CBS Chief Executive Leslie Moonves sought to allay Wall Street's fears during a conference call to discuss the company's earnings: "We have a full slate of new first-run programming ready to go, both now and at midseason. We would anticipate no material impact on the company for the remainder of the television season."
CBS' comedies and dramas repeat well, maintaining about two-thirds of the audience of their first run. That should help CBS with its advertisers.
CBS might be hamstrung on a separate front. A group of WGA members, news writers, editors and others who work for CBS News and some local stations, have been working without a contract and plan a Nov. 15 strike authorization vote.
Fox Broadcasting, owned by Rupert Murdoch's News Corp., is in the best position for a strike. The network programs seven hours fewer a week than its rivals. It will air the popular college football Bowl Championship Series during the holidays and its juggernaut, "American Idol," returns in January.
Analysts also believe that ABC could suffer in a strike. The Disney network's top shows, including "Desperate Housewives" and "Grey's Anatomy," don't repeat well. To help keep its ratings strong, ABC has ordered more reality shows than usual. ABC can also dip into Disney's library of movies and old TV shows.
"Disney's decision to increase television production while simultaneously scaling back film production would also increase the effects of an extended strike," Lehman's report says.
It is unclear how NBC might fare. The network is off to a lackluster start this season, with its new shows sputtering. NBC plans to run more reality shows, including "Amnesia" from Mark Burnett and a remake of the 1990s show, "American Gladiators." It also plans to air on NBC some of its sister cable network's shows, such as "Project Runway" or "Law & Order: Criminal Intent."
"In 1988, the television ratings dropped by about 8% and that figure could double 20 years later," said Spengler, the ad buyer.
If the ratings fall short of the guarantees to Madison Avenue the networks made in June, when they sold the bulk of their ad inventory, advertisers would receive additional commercial spots to make up for lower ratings. Advertisers also could cancel their orders if they didn't want spots to appear in a replacement show. Such cancellations could take a bite out of the networks' profits.
RDF's Coelen noted that reality shows became a permanent part of the television fabric after the last threat of a writers strike in 2001. Networks saw reality shows as cheaper alternatives to scripted shows.
Coelen predicted that a strike could force networks to expand beyond home-grown scripted shows and reality formats to become a bigger buyer of shows that have worked overseas.
"A strike would be a bad thing for the whole industry, but if there is one silver lining, it might make people think in a more creative and different kinds of ways," he said. "And that could be healthy for the business."
Times staff writer Maria Elena Fernandez contributed to this report.