The Jane Austen fan club is real, it is global, and if you question its power, just step into any bookstore and utter the word “overrated” in the general direction of a copy of “Emma.” (Then duck.) But what drives the mania? “Why can’t folks get enough of Austen’s Regency-era escapism that typically features a boy, a girl, a great love story, only a hint of sex, the great divides of class and money, plus an abundance of heaving bosoms and tight breeches?”