From the November issue: While vacancy signs have been proliferating along the avenues of many of the city’s established shopping districts throughout the downturn, major chain stores are moving into massive new malls located in former retail dead zones in places like the South Bronx and East Harlem. These new multilevel malls — many of which are on former industrial sites — are different from the big-box stores that made inroads into many parts of the city in recent years. They boast even larger floor plates, often allowing a store to consolidate all of its operations on one level. That, in turn, has the potential to attract the types of warehouse stores and wholesale outlets typically found in the suburbs and less dense parts of the outer boroughs. Indeed, later this month, Manhattan’s first Costco is set to open at East River Plaza, a new half-million-square-foot mall located between East 116th and 119th streets along the FDR Drive. Next year, a slew of bargain stores will also be opening at the mall, which was developed by the Blumenfeld Development Group and is 90 percent leased out. Tenants will include Best Buy, Marshalls, and Bob’s Discount Furniture.