Of the many hypocrisies of which the Coalition stands accused, one which has worried me least is its habit of giving tax credits to film companies. I like films, I like stories about Glasgow being closed for days so that Brad Pitt can battle zombies there, and I like the fact that we're encouraging people to use our many excellent film-makers.
But health researchers find the whole idea a lot more troubling than I do. Christopher Millett, from the School of Public Health at Imperial College London, has been doing the maths, and found a problem. The British government spends twice as much cash on subsidising films which feature smoking as it does on mass-media anti-smoking campaigns.
Feel free to read that again and try to work out what the connection might be. I've read it several times and I'm no nearer. The director of research at Action on Smoking and Health agrees, though, saying: "The research is clear: the more a young person sees smoking in films, the more likely they are to try smoking themselves."
But how can that research be clear? How do you find children who have seen smoking on film, but not on telly, or on the street, or in their homes, or in the houses of their friends? How do you isolate film as the guilty party?
Besides, I just don't believe that films which show things are identical to films which promote things. As a child, I watched the film Highlander so many times that I still know the dialogue by heart ("Nuns – no sense of humour"). But never once did I think it was advocating the beheading of my fellow immortals. Sometimes, it's not an example, it's just a movie.
Recent UK-subsidised films which showed people smoking include, among others, Quantum of Solace, Sherlock Holmes and Nine. Yes, Nine, a musical based on Fellini's 8 . Try as I might, I can't envisage any impressionable infants using their pester-power to be taken to that rather than the latest Harry Potter. And I like a musical.
To be honest, if you're going to take your kids to see Quantum of Solace, you should be more worried that they'll die of boredom than lung cancer. And Sherlock Holmes, you probably remember, smokes a pipe. Seen any impressionable teens sporting one of those lately? Looting the pipe shops to get their coveted Meerschaum the other week? Me neither.