Whenever Hollywood's box office slips, as it did last month,* puzzled moviemen ponder such possible causes as the weather, the crops and the local bingo games. Last week a fledgling producer, Novelist Polan (There Goes Lona Henry) Banks, offered a fresher theory: Hollywood has been underestimating the power of a woman. Banks told the Motion Picture Herald:
"No other American industry, great or small, has forgotten that women own about 70% of the nation's wealth and control an even greater percentage of its buying. More than 90% of the country's advertising is directed at the woman . . . but postwar [motion]...