Assessing the legal value added of collective bargaining agreements

Labour law can be established both by statutory law and by collective bargaining. How much value does the latter effectively add? In this paper we propose a methodology to address this question: we compare the specific contents of collective agreements (except minimum wages) to their equivalent norms set by statutory law (if any). We illustrate this approach by analysing in detail over 400 norms from six collective agreements in Portugal and then comparing them to the country’s Labour Code. We find that as many as 59 % of those collective bargaining norms are exactly or virtually equal to the Labour Code; only 27 % (an average of 16 norms per convention) are more favourable for the worker; and 11 % (8) are more favourable for the employer. We conclude that collective bargaining in Portugal has a relatively small role as an effective source of labour law. We also present several potential explanations for our findings, including the wide range of statutory law.