The Media Rating Council said that Nielsen's numbers during the COVID-19 pandemic undercounted viewers, as was alleged by networks and distributors represented by the VAB.
In a statement, MRC said it believes that total usage of television by persons 18-49--the key demo used to sell advertising--was understated by approximately 2% to 6% for the February 2021 measurement period.
The MRC added that persons using television estimates that persons using television estimates in the persons 18-49 group was understated by a range of 1% to 5% in February 2021.
VAB CEO Sean Cunningham said the MRC statement was “just the tip of the iceberg,” He noted that it contradicts what Nielsen has been saying and calls for "greater scrutiny" of the situation.
The MRC estimate of Nielsen’s undercount covers just one month. Cunningham noted that in February, TV ad spending, according to Nielsen was $3.9 billion. A 1% undercount would represent $468 million and 6% would be $2.8 billion.
The undercount, according to the VAB was the result of changes in the way the Nielsen panel was maintained during the pandemic. COVID-19 protocols meant Nielsen couldn’t send its field people into people’s homes. As a result, some homes that were no longer watching TV for unclear reasons were left in the sample.
Cunningham noted that Nielsen's earnings last week contained $100 million in operations cost savings from having closed field and call centers. That means Nielsen profited from the changes it made in maintaining its sample, he said.
In its statement, the MRC noted that "the impacts to estimates will vary among different demographic groups and dayparts, and percentage differences, when applied to program estimates, can be misleading because of the small size of the absolute ratings of many programs, which can distort change percentages,"
MRC also notes, and users of the data "should keep in mind, that this range of impact, as well as the originally reported ratings themselves, are estimates with standard errors associated with them. However, we believe the directional impact noted above is appropriate to consider in assessing the estimates originally reported by Nielsen."
Nielsen said that the analysis released by the MRC was implemented by Nielsen as requested by the MRC.
Nielsen noted that 93% of C3 ratings for people 18 to 49 for major networks saw no more than a 0.02 change in ratings points.
“We will continue to work with the MRC on other analyses in the future.,” Nielsen said. “Throughout the pandemic, Nielsen has been fully transparent in collaborating with the MRC and focused on procedural changes to support its panelists, people and the integrity of currency metrics used by the industry.”
Nielsen added that it has “aggressively returned to pre-COVID maintenance procedures and will continue to rigorously work with the MRC and its clients to understand the impacts of both the pandemic and changing consumer viewing behaviors on data and analysis.”
VAB's Cunningham said that Nielsen's biggest clients, the TV networks and distributors, began noticing "defects" in Nielsen data in April 2002. The tip off was the the Nielsen data was showing drops in total TV usage, whether linear TV, streaming or gaming.
"Unbeknownst to clients, they had made extensive changes" in June of 2020 to procedures that led to homes that in normal times would have been excluded from the sample being left in last year.
Overall the size of Nielsen's sample dropped 20% to 29,500 homes. But another 9,400 homes, or 32% of those remaining, were impaired or malfunctioning, Cunningham said.