In Paris during the winter of 1943–44 a mathematics student was attracted by economics. Without the guidance of any professor, he was trying to understand various books dealing with this field. One day he entered the little shop of a publisher, rue de la Sorbonne, and bought a book with the fascinating title Les fondements mathématiques de la stabilisation du mouvement des affaires (Mathematical foundations of the stabilization of business fluctuations). The author was an ‘expert temporairement attaché à la Section Financiére et au Service des Etudes Economiques de la Société des Nations’, J. Tinbergen. As he was studying the book very carefully, this young man could not imagine that forty-five years later he would be given the honour of delivering the Tinbergen Lecture.

Today, then, I am paying tribute to one of my best teachers, one whom I did not bother with questions but who with this book played an important role in my economic education. Probably my approach to economic phenomena was to a significant extent shaped by what I then learned from Jan Tinbergen.

The subject of this lecture concerns what has been the main question motivating my research during the last decade, namely the medium-term relationship between wages and employment. This question concerned Tinbergen fifty years ago and was indeed very much discussed at the time.