A Search Model in a Segmented Labour Market: the Odd Role of Unions

Assuming random matching productivity, we present a search equilibrium model where each match ends in a vacancy, in a temporary job or in a permanent job. Centralized bargaining sets the wage rate of permanent workers whereas rms decide unilaterally the wage rate of temporary workers. In this segmented labour market: a) the wage setting function can be downward sloping; b) higher union bargaining power leads to higher wage and higher unemployment; c) average worker productivity shows a maximum with respect to union bargaining power.