In memoriam Piet Verheyen

Piet Verheyen combined research and teaching with the university administration and with additional external functions. Among his other positions were the chairmanship of the board of directors of the Maria Hospital and the hospital R.K. Gasthuis, the chairmanship of the Museum of Natural History in Tilburg.

As an administrator, Piet was a heavyweight within the university. He was Dean of the Department of Econometrics (1968-1971 and 1984-1985), Dean of the School of Economics (1968-1971 and 1986-1987), member of the Executive Board (1971-1973, 1985 and 1993), President of the Executive Board (1988-1991). In this capacity he managed important student revolutions, such as the Karl Marx University. He also put KUB, the university in Tilburg of regional significance, on the world scientific map by supporting the establishment of the CentER institute. In addition, he was a board member of several foundations including the Tilburg Economic Institute, Kennedy Institute, Institute for Social Scientific Research (IVA), and the Cobbenhagen Fund/TAEK.

Career
Piet Verheyen was born in Alphen in 1931. After primary and secondary school he began his studies at the then Catholic Economic College in Tilburg. He graduated cum laude with a specialization in business economics and obtained his doctorate in 1962 from Professor D.B.J. Schouten with the thesis Economics and Technology. Piet started his career in 1959 at the State Mines in Heerlen, where he was successively employee, deputy chief and chief of the statistics department. Until 1966 he combined his work in Heerlen with an appointment at our university. In 1962 he became Extraordinary Lecturer, which was converted into an Extraordinary Professorship in 1964. From 1966 to 1996, Piet was full time Professor of Business Economics.

As a professor, Piet has been of primary importance to several generations of econometrics students. In the 1960s, together with fellow professors Koos Kriens, Max Euwe and Jan Dalmulder, the study of econometrics was launched. Piet's specialization was business econometrics. He taught students a way of thinking that focused on translating the solution to a mathematical problem back into economic reality.

Pete also made his mark as a researcher. A conference in his honor was the beginning of the world-renowned CentER at our university. Besides several books, he published more than 60 articles in scientific journals and supervised 18 PhD students. He was particularly interested in topics such as the non-profit sector, the value of the enterprise, and investing and financing in a dynamic environment. Regarding the latter, it was of great importance that he stood at the cradle of the Tilburg school of Optimal Control Theory, which developed an international reputation. He was unique in his way of combining mathematics and economics. His characteristic question "you solved this mathematical problem beautifully but what does it actually say?" lives on in the work of his scientific children (PhD students), grandchildren and great-grandchildren (PhD students of Piet's PhD students).

Piet's impressive life accomplishments have not gone unnoticed. He became a Knight in the Order of the Dutch Lion and a Commander in the Order of Saint Gregory the Great.

We wish Jeanne, his children and grandchildren much strength in coping with this great loss.

Peter Kort, Professor of Dynamic Optimization in Economics and Operations Research, Pieter Ruys, Emeritus Professor of Mathematical Economics, and Dolf Talman, Emeritus Professor of Game Theory and Equilibrium Programming at TISEM, Tilburg University.