Hollywood has always been an international business, but it is becoming dramatically more so. In the past decade total box-office spending has risen by about one-third in North America while more than doubling elsewhere (see chart). Thanks to Harry Potter, Sherlock Holmes and “Inception”, Warner Bros made $2.93 billion outside North America last year, smashing the studio’s previous record of $2.24 billion. Falling DVD sales in America, by far the world’s biggest home-entertainment market, mean Hollywood is even more dependent on foreign punters.