The Silver Arrows have dominated this season, winning all seven races to date.
That means Lewis Hamilton leads team-mate Valtteri Bottas by 29 points in the drivers’ standings ahead of this weekend’s French Grand Prix.
And Carey thinks the dominance will mean the viewing audience for Formula One is unlikely to increase.
His comments could worry Mercedes with regulation changes on the horizon.
“Basically I would say that the figures are by and large stable,” Carey told Speed Week.
“But I have to admit that in 2019 there will not be anything dramatic in that area when one team is winning all seven races so far,” he added.
“And some races were not exactly exciting all the way to the final lap, even if in Monaco and Montreal we at least had fights at the top until the end.”
Carey also opened up on next season and what races we can expect to see on the calendar.
He explained: “We discussed a lot, but did not negotiate specifically.
“Of course we want to continue to come to Austria, this is one of the most popular races in the calendar.
“For 2020, we have confirmed the new locations Hanoi and Zandvoort. The calendar will be announced soon.
“Our goal is to bring Formula One into previously unmet markets, such as Africa or a second region of the US.”
Meanwhile after Sebastian Vettel’s error two weeks ago in Canada, Hamilton insists he takes no notice of his rivals.
“I don’t know, I don’t really look too much,” he told Racer.
“I don’t compare myself to other people so I don’t look to others or their faults or anything.
“I just look to really try and take a lot of pride in my work and particularly my track record of not making mistakes, which I’ve managed to get myself into a really good place and deliver minimal faults in race weekends and races.
“I had a small hiccup on Friday (in Canada) but was able to pull it back on Saturday and then throughout the weekend, so that’s a real, real focus.
“21 races, every single point counts — even seven points, or three points, it adds up, so I take a lot of pride in that.”
The French Grand Prix gets underway at 2.10pm BST on Sunday.