For decades, America's biggest retailers weren’t just where you went to buy clothes or appliances. They were the anchors for downtowns, filled suburban malls and shaped how generations shopped. Now many of them are hanging on by a thread. Some, like Sears and Kmart, are on the verge of extinction. Saks Global has declared bankruptcy. Must Read Others, like Kohl’s, are shrinking, restructuring or struggling to stay afloat. On a recent Freakonomics podcast, retail analyst Mark Cohen described Macy’s st ...