Although a post-Christmas blizzard snowed in shoppers across the Northeast during the final week of the month, the real problem was the economy, according to Robin Lewis, co-author of \”The New Rules of Retail,\” a new book that explores the fresh challenges facing the industry.

\”A lot of the expectations for the holidays were pinned on hope and hype,\” said Lewis, who instead blamed stiff unemployment and a moribund housing market — two dampers that he doesn\’t expect will let up in 2011.

READ MORE: \”All Hope and Hype\”