Shoppers at Walmart. The Walton family runs the world’s largest retailer. The post-crisis numbers are in, and it paid off to be a patriarch. Think back to the height of the panic that was toppling global banks in late 2008, and a story from São Paulo sticks out. With its share price down more than 30 percent, Brazil’s Banco Itaú struck a deal to merge with União de Bancos, its foremost rival. Both banks needed to expand their reach and share costs, but a more fundamental fact made th...