In hard times, people tighten their belts and curtail their buying. But some product lines resist the urge for tightening, and groceries is one of them. My idea for today is called Companhia Brasileira de Distribuicao (CBD), which is the second largest retailer in Brazil, a giant chain of nearly 600 stores with about 66,000 employees. The company operates a number of different chains that target different demographics, including Pao de Acucar (high-end supermarkets), CompreBem, Extra Perto and Sendas (value supermarkets), Extra (hypermarkets, which put all classes of merchandise under one roof), Extra-Eletro (electronics and home appliances) and Extra...