My research interests are the management of ethics, the ethics of management and the measurement of ethics.

I started my research in the early 1990s with studying the frequency and content of codes of conduct among Dutch companies. At that time 22% of the one-hundred largest companies in the Netherlands had a code. The result was a booklet published by the Dutch employer association NCW.

After that, I started my Phd-research into how to manage the ethics of organizations. The first question was: what is the ethics of an organization? Following Solomon’s virtue-based theory of business organizations, I defined the ethics of an organization as the extent to which the organizational context promotes ethical behavior and impedes unethical behavior of its managers and employees. To define the desirable ethical organizational virtues, I conducted a qualitative analysis of 150 diverse cases of unethical behavior. The resulting list of cultural items was categorized into eight organizational virtues. To measure these virtues, I developed a questionnaire. At the end of my PhD-thesis, which I defended in 1998, I come up with a variety of instruments for improving each specific virtue.

After my PhD I started to study the ethics of managers. What is an ethical manager and what is an unethical manager? Part of this work has been published in the book “The Six Principles of Managing with Integrity” of which an earlier version was published in Dutch in 2002.

In 2002, the textbook “The Balanced Company” co-authored with Johan Wempe was published at Oxford University Press. In this book we develop a corporate integrity theory. A central typology in the book is the distinction between three types of moral dilemmas companies are confronted with: the dilemma of the dirty hands, the dilemma of the many hands, and the dilemma of the entangled hands.

Between 2003 and 2006 I did, together with my colleagues of Erasmus University, Pursey Heugens and Hans van Oosterhout, some conceptual work in social contract theory and virtues theory, resulting in publications in Academy of Management Journal, Organization Studies, and Journal of Management Studies.

In 2008, two papers were published on scale development regarding the ethical virtues model and unethical behavior, in Journal of Organizational Behavior and Journal of Management respectively.

In 2011 a paper of mine was published in Human Relations about the relationship between ethical culture and unethical behavior. Since then I conducted empirical research into the effectiveness of ethics programs and conceptual research about leadership in ethics, ethics as struggle, and the appearance of unethical behavior.