Ever wonder what goes on behind the scenes at a Broadway show? This week's EconTalk lifts the curtain on the magical world of Broadway: Mitch Weiss, co-author of The Business of Broadway, talks with EconTalk host Russ Roberts about his book and what it's like to manage the production of a blockbuster musical in New York City. Topics discussed include the eight-performance-per-week grind, the how…