In early August, lower-than-expected subscriber numbers at ESPN caused Disney to lower its forecast for cable operating income growth. We then witnessed almost $50 billion being wiped off the combined value of the biggest TV content producers, including Disney, Time Warner, Fox, CBS, Viacom and Discovery Communications. The Dow Jones U.S. Broadcasting and Entertainment Index continued to fall, ending 15% down from the beginning of the month.

The concern on Wall Street is that increasing numbers of subscribers are ‘“cord-cutting” – abandoning cable altogether or opting for slimmer channel packages in favor of subscription video-on-demand (SVOD) platforms such as Netflix, Amazon Prime and Hulu Plus. Investors also are worried that media companies aren’t earning enough from SVOD platforms to compensate. Reliable measurement of those platforms is needed to determine whether that’s true.

Nielsen’s count of multi-channel TV subscribers supports the belief that there has been a decline from 100.721 million households at the end of the first quarter to 100.149 million households at the end of the second quarter.

Nevertheless, we think Wall Street’s concern is overstated because it does not account for seasonality. Cable subscriptions tend to rise in the fall and winter and drop in the spring and summer. When we adjust for seasonality, the loss for the past year is approximately 1.2 million households, not the 2.3 million that annualizing the second quarter number would generate.

But the pressure is real. Multi-channel subscriber counts are being squeezed by the rise of subscription-based streaming services. At the same time, TV advertising revenues are pressured by declining ratings as consumers spend more time on SVOD and other video services, and by competition for marketers’ dollars from newer digital video channels such as YouTube and Facebook.

Analysts such as Bernstein’s Todd Juenger estimate that the license fees paid by SVOD providers to big content owners are between $3 billion and $4 billion annually, and that the multi-channel TV market has approximately 100 million households paying $80 a month, approximately half of which goes to content owners. Combine this with potential national advertising revenue, and you are looking at a $100 billion market.

When streaming services first emerged, the viewing they attracted was largely additive to TV viewing, making any license fee revenues a great deal for content owners. However, if the $3 billion to $4 billion in fees is compromising $100 billion in subscription and advertising revenues and curtailing future growth, the pricing needs to be revisited.

Recently announced deals for programs such as “Sesame Street,” “Seinfeld” and the new program featuring the “Top Gear” hosts have featured heavy increases in license fees. Even with these increases, are current prices a good deal for the media companies, who have increasingly licensed their content to SVOD providers?

To understand the value of content on SVOD services, content owners need to understand how many people are watching, their demographic information and how their content compares against other programming. This transparency should come from industry-wide measurement directly comparable to today’s TV ratings. This would also help prevent the ‘prisoners dilemma’ faced by media companies should they decide to pull their shows and films from SVOD services, only to learn that peers haven’t followed suit.

Only comprehensive, independent and comparable measurement of audience behavior on SVOD services will make it possible to get license fee pricing right. Services such as Netflix periodically report some information to content owners, such as how many people viewed their programs. However, this metric does not include two essential components required to enable rights owners to compare the value of an “eyeball” on ad-supported TV to one on an SVOD service – a total market view of all SVOD programs and services and a count of unique viewers.

In December of last year, Nielsen announced plans to measure SVOD services like Netflix, and today we are working with a number of studios to help them understand audience viewing of programs through the use of audio signatures.

However, full measurement for every program, reported daily, in a format directly comparable to the existing ad-supported TV ratings is required to solve the license fee dilemma.  This requires rights owners to insist that watermarks be carried on all SVOD services as they are on most other forms of TV and video. This will go a long way to restoring much needed balance to – and confidence in – the media sector.

This article originally appeared on the Wall Street Journal’s CMO Today.