Is Wal-Mart an inferior good?

An inferior good is one whose income elasticity of demand is negative, so that when income goes down, demand goes up. From NY Times:

Sales at department stores and specialty retailers are falling rapidly. They are cutting staff, discounting merchandise and liquidating stores to survive. But even as the financial turmoil strangled discretionary spending at many stores, it sent struggling consumers into the arms of Wal-Mart — and left it, the world's largest retailer, poised for a blockbuster Christmas.