Profits and Competition in a Unionized Duopoly Model with Product Differentiation and Labour Decreasing Returns

In this paper, we aim at investigating if the conventional wisdom, that an increase of competition linked to a decrease in the degree of product differentiation always reduces firms’ profits, remains true in a unionized duopoly model with labour decreasing returns. In this context, mixed results emerge. In particular, we show that a decrease in the degree of product differentiation may affect wages, hence profits, differently, depending on both the mode of competition in the product market (Cournot or Bertrand competition) and the particular unionization structure (firm-specific or industry-wide union(s)). Interestingly, it is shown that the conventional wisdom can actually be reversed, even if under Bertrand competition only.