When the door to a TLA Entertainment video store swings open the primary question facing most consumers shuffling inside is relatively simple: ”What movie will I take home tonight?” But to Wharton marketing professor Jehoshua Eliashberg and Wharton doctoral candidate George Knox the key question surrounding the burgeoning $12 billion home-video market goes at least one step further: Which consumers will rent their movie of choice tonight and which consumers will buy? In a study entitled ”The Consumer’s Rent vs. Buy Decision: The Case of Home-Video ” Eliashberg and Knox present a new model that they say accurately predicts the consumer’s decision to rent or buy a particular movie at a video store.