Institut für Volkswirtschaftslehre
The publications of a scientist over his/her career are usually not evenly spaced in time. Productivity patterns quite often show an intuitively plausible time course: scientific creativity tends to rise rapidly to a peak and then gradually declines. There are many studies of career paths of creative people since the famous statistician Quetelet (1835) started pertinent research almost 200 years ago. Typical life cycle patterns are not only observed in academia, but also in artistic production, in criminal behavior and other fields.
One important purpose of the present paper is to explain how such a diversity might come about. While virtually all models dealing with the dynamics of scientific production are descriptive, in what follows we propose a normative approach. We depart from the assumption that a scientist starts to invest in his human capital, working behind the desk, reading books and papers, developing new ideas, etc. Once a certain stock of knowledge has been built up, the scholar can fruitfully work on his/her reputation. Investing in this stock one does by presenting at conferences, contacting colleagues, networking at receptions, etc. These efforts can be summarized as networking investment. The output of a scientist is publishing papers. Necessary for that is the accumulation of a sufficient stock of human capital, while reputation may act as another important production factor. The aim of the scientist is to maximize the discounted stream of publications over time taking into account the costly investments. The dynamics of the system is given by two ordinary differential equations. Solving the resulting optimal control model by using Pontryagin’s maximum principle shows that the shape of the optimal paths depends crucially on the initial situation. If the stock of knowledge is initially too small, it turns out that the researcher’s career will not be very productive. If, however, a certain human capital endowment (the so-called Skiba-threshold) is exceeded initially, the career will flourish.
em. o. Univ.-Prof. Dr. Gustav Feichtinger
Technische Universität Wien
Christina Kopetzky (vwl2 [at] aau [dot] at)