labour law has for the labour market or for the society as a whole. This would be an extremely ambitious and complex approach. And it only could be fruitfully started in an interdisciplinary effort, it would go far beyond the competence of legal experts. And even then it would be doubtful whether reliable results could be identified. Therefore, this paper does not attempt to contribute to this debate at all. The perspective here is much more modest. Effectiveness in the sense used in this paper exclusively refers to the question whether and in how far the normative framework of labour law is implemented in actual reality