“We need more graphics!” says Ron. “We already have quite a lot,” a technician replies, warily. But Ron gets his way, and his financial bulletins end up looking like he is trapped in the central reservation of a six-lane motorway for share prices. News, he insists, should be exciting: it should pander to viewers’ prejudices, broadcast live car-chases and tend towards either the cuddly or the coarse. The station acquiesces. Ratings, of course, go through the roof.

Has Ferrell decided, 10 years into a broadly fruitful Hollywood career, that his films had better start meaning something? Until recently, his work with director Adam McKay, who shares a writing credit here, has always been scrupulously stupid, but their last picture together, The Other Guys, featured a billion-dollar investment scam not unlike the one operated by Bernie Madoff, and we saw flickers of a social conscience at work.

Well, either way, the new material here is mostly funny, and the satiric arrows, frankfurter-thick as they are, find their targets more often than not. The fashions of the era, too, are brilliantly caricatured – although there is only a hair’s-breadth of silliness between the blaring ties and windproof hairstyles here and in American Hustle, David O. Russell’s 1970s-set caper film.

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Yet in the same way that old bands feel obliged to roll out their greatest hits in concert, Anchorman 2 retreads many of the first film’s jokes and ideas, and in these moments, it feels more like a schematic cash-grab. Old characters meet new matches, or at least vague doppelgängers: Ron finds a rival in a younger, more snappily dressed newscaster played by James Marsden, and the simple-minded weatherman Brick Tamland (Carell) falls in love with an even simpler-minded secretary played by Kristen Wiig.

Ferrell’s comic energy is fuelled by unpredictability, so jokes that pre-empt their own punchlines are hardly ideal, and accordingly, neither scenario delivers quite as many laughs as you might hope. Nor does a sequence in which Ron has dinner with his boss’s family, who are black, and tries to talk as he imagines black people might – although there are flashes of Sacha Baron Cohen-calibre cringe comedy here.

Happily the film finds its feet again in its third act, with a subplot so strange I half-suspect I dreamt it. (Recounting the details would only defuse them, but it involves blindness, a lighthouse and an orphaned shark.) The sequence isn’t pure Anchorman, but it is pure Ferrell, and brings the film in for a smooth landing. The legend loses something in the retelling, but what’s new here is mostly worth the trip.