• by Wayne Friedman , November 13, 2017

Third-quarter national TV advertising posted its third consecutive quarterly decline, with the fourth quarter expected to be the same, according to one analyst.

The national TV marketplace for the third quarter overall sank 1.9% -- excluding the Summer Olympics of a year ago. It was down 10%, including the Olympics, to total $8.5 billion, says Michael Nathanson, senior media analyst for MoffettNathanson Research.

Worse, he says there appears to be a slowdown in near-term “scatter” TV advertising sales -- especially for cable -- in the relationship ratio between TV ratings and advertising revenues.

“The third-quarter gap between ratings and advertising growth closed completely for the first time in eight years,” says Nathanson.

Nathanson said this analysis is for "total day revenue weighted viewership growth," which was down 5% in the third quarter, and domestic cable advertising growth, which was down 1.6% for the period — excluding the Summer Olympic comparisons of a year ago.

“That’s a bearish sign, as it suggests scatter demand has slowed,” he writes. That said, he adds that there is a “somewhat imperfect correlation between ratings and advertising.”

Overall, national TV cable networks in the third quarter -- including Olympic-related advertising of the year before -- were down 4.2% to $5.1 billion for major cable TV network groups.

Broadcasting networks fared worse -- given the Olympics programming on the NBC broadcast network -- down 17.4% to $3.4 billion. With the Olympics, U.S. broadcasters' core advertising was down 2.3%.

Nathanson says national TV third-quarter advertising commercial loads were down 1%, slightly reducing most networks' inventory.