Nielsen under fire after admitting US TV ratings mistake going back seven months

The error wound up benefiting one network, ABC, while negatively affecting the others, according to people briefed on the problem, said the Times.

In a telephone call with reporters, Nielsen executives would not confirm that it had resulted in added viewers for ABC, saying they could not discuss individual clients.

But an ABC executive confirmed that the error had improved the network’s ratings. As for Nielsen, its executives played down the discrepancy in viewing totals, saying they fell between 0.1 percent and 0.25 percent of the viewing totals.

It remained unclear how the mistake would affect the billions of advertising dollars based on Nielsen’s ratings, as well as the company’s reputation.

The Times said several television and advertising executives expressed degrees of anger and incredulity at both the incorrect ratings and the amount of time — seven months — it had taken to discover the problem.

“These ratings are the currency of the business,” said Alan Wurtzel, who heads research at NBC. “Any time that currency is under suspicion it’s a concern.”

Lyle Schwartz, a managing partner in charge of research at WPP’s GroupM, the world’s largest media buying group, said it was a credibility issue for Nielsen.

“You look at Nielsen as the gold standard for currency,” Schwartz told the NYT. “When you introduce these errors on systems that were working fine in the past, you start looking at the numbers a little bit closer to see if there is anything else occurring that we haven’t identified yet.

Nielsen ratings are the currency on which nearly $70 billion in advertising dollars are traded each year in the United States, said the Times.

“The company has come under increased pressure in recent years as television and advertising executives have called its methodology antiquated and questioned its ability to measure the ways people watch television today.”

Outsiders, including Rentrak and comScore, are challenging Nielsen’s dominance by introducing methods to track TV viewing in the digital age.

Even if the ABC gains were entirely legitimate, they now have a shadow over them. ABC issued a statement on Friday saying that despite the error, the network was confident that it would maintain the ratings momentum that its programming has seen in the opening weeks of the new television season.

The Nielsen executives Pat McDonough and Steve Hasker said repeatedly in their news conference on Friday that the incorrect ratings — which had affected every program on ABC, not just the ones in prime time — fell “well within the tolerance of statistical error.They would be corrected when Nielsen issues new ratings tomorrow.

But in a statement sent to clients, the company said, “In the vast majority of cases the impact is small, but in a handful of cases the impact is more material.”

The Nielsen executives blamed a new software program that was introduced in March.

The error was most noticeable in changes in reported ratings between the first available numbers — which arrive each morning — and the more complete “fast national” numbers, which arrive in the late afternoon.

Network executives, including those at ABC, began to notice recently,that ABC’s programs were frequently showing improvement in the second daily accounting — something that usually happens only with the biggest hit shows.

CBS, for example said the NYT, detected on the first night of the new television season that ABC’s “Dancing with the Stars,” a, show in decline for years, got a bump up in the ratings in the afternoon rankings, even though two big ABC-affiliated stations had not even carried the show the previous night.