The change could hurt the ratings of some English-language TV networks while providing a boost to those of Spanish-language channels such as Univision and Telemundo.
Nielsen tracks the viewing habits of 5,000 U.S. households and uses those numbers as the basis for national ratings for broadcast, cable and syndicated programming. In a client notice dated May 3, Nielsen said its U.S. Households and Persons Estimates for the 2001-2002 season, based on projections supplied by statistical researcher Claritas/Market Statistic, would change to reflect a 10% to 13% rise in the number of Hispanic households as reflected in the census.
"The 2000 census serves as the new benchmark, and estimates may not trend as well as with prior years," the notice said.
As a result of the rise in Hispanic homes, advertising agency research analysts naturally expect Univision, Telemundo and the forthcoming Azteca America to gain from the increase. "This doesn't bode well for network affiliates because Hispanics have more of a tendency not to watch network television, more than Afro-Americans and whites," said Brad Adgate, senior VP-media research for Horizon Media, New York.
Separately, Nielsen said preliminary estimates are that it will raise its overall U.S. household universe by 3.2% to 105.5 million from 102.2 million this year because of census data. The total number of viewers could also climb for the new season, as viewers 2 years old and older are expected to gain 3.0% to 269,690,000.
Jack Loftus, VP-communications for Nielsen Media Research, said the 3% gain will be spread out among all markets, except for Los Angeles, which already was adjusted higher last year.
The national household increase may be good news for TV networks. The increase in overall TV households by more than 3% is almost double the jump in noncensus years, said Debbie Solomon, senior partner, group research director, WPP Group's MindShare USA, who noted the normal annual increase in Nielsen TV households ranges from 1.0% to 1.5%.
"This kind of helps all cable networks," said Mr. Adgate. "If you are at 75% [penetration] or 85%, suddenly you have a lot more homes."
Advertisers might also benefit. The rise in households could lower pricing, suggested Ms. Solomon. "With the new numbers, CPMs will go down a little, but it will just be a tiny bit smaller."