Luiz A. Esteves Federal University of Paraná and University of Siena   Avenida Prefeito Lothário Meissner, 632 Jardim Botânico Curitiba, PR 80210-170 Brazil   esteves@ufpr.br   http://www.sitenarede.com/luiz_esteves/           JEL Areas: J3 : Wages, Compensation, and Labor Costs: General G3 : Corporate Finance and Governance: General