"Reason to Believe" by Mat Coward, in Death By Horoscope, edited by Anne Perry, Carroll and Graf, 2001.
Ran across this 2001 collection at the library and it had a lot of good authors (Block, Rusch, Lovesey, etc.) so I thought I'd give it a try. Some of the stories assume astrology is real, some assume it is bogus. I, a definite bogus-er, enjoyed some of each, but this was the stand-out.
In a funny story, what exactly is funny? It could be the language. It could be the narration (not quite the same as the language.) It could be situation. It could be character.
I think one of the reason so many of Donald E. Westlake's books were made into bad movies was that a lot of his humor is in the narration, and that doesn't carry over onto the screen at all. And speaking of language, I remember Stephen Fry complaining when he portrayed P.G. Wodehouse's Jeeves that the first time Jeeves appears in the books, he "shimmered" in. How exactly was Fry supposed to "shimmer in?"
The humor in this story is mostly character-based. Specifically it revolves around our hero, DS Harry Peacock of the Metropolitan Police. Harry has a somewhat eccentric view of the world and conducts an ongoing conversation with himself that cheerfully overflows in ways that baffle his companions and delight the reader.
Peacock is no fool so when he is talking to his boss his rebellious thoughts stay inside.
"OK. You all right to run with this for a little longer?"
Harry wondered what would happen if he said that, in fact, non, he wasn't OK to run with this, that, in fact, he rather thought he'd spend the rest of the day swmming in the lido. It WAS a hot day. He wouldn't mind a swim.
"Yes sir," said Harry.
Later someone threatens to report him to his superiors and Harry replies: "I have no superiors... They're small men with mustaches."
The story has a plot. Did I mention that? A man who doesn't believe in astrology has been regularly meeting with an astrologer and now he has disappeared. Harry has a strong suspicion as to what has happened and eventually he proves it. But along the way we get conversation like this one with the horoscope scribbler.
"Astrology is not as hot as it was when I started up. The public is fickle."
Harry gave a sympathetic nod. "Those feng shui bastards, eh? Coming over here and stealing our jobs."