Frans van Dijk

Incentive Systems in a Real Effort Experiment

In the reported experiment different payment schemes are examined on theirincentive effects. Payment based on individual, team and relative performance are compared. Subjects conducted computerized tasks that required substantial effort. The results show that individual and team payment induced the same effort levels. In team production free-riding occurred, but it was compensated by many subjects providing more effort than in case of individual pay. Effort was higher, but more variable in tournaments, while in case of varying abilities workers with relatively low ability worked very hard and drove up effort of the others. Finally, attitudes towards work and other workers differed strongly between conditions. This discussion paper has led to a publication in the European Economic Review 2001, 45(2), 187-214.

Dynamics of social ties and local public good provision

Abstract A model is presented in which social ties between individuals and private contributions to a local public good are interrelated. Ties are formalized by means of utility interdependence, and depend on the history of social interaction, in this case the joint provision of the public good. The resulting dynamic model generates equilibrium values of the intensity of ties and the private provision level. The impact of public provision on these variables is analyzed. Our results are very different from those obtained with the standard model, where individuals are only interested in the utility from own consumption.

Decision Making about the Environment: The Role of Information

The recent upsurge of concern about the environment is partly a result of the visible degradation of our surroundings. But an even more important role in raising awareness is played by information. In particular, new information about worldwide issues like climate change and ozone depletion, as well as about local problems like dioxine pollution, is essential in this respect. The strategic presentation of such issues in the Brundtland report and follow-up reports published in some countries magnified the impact. In the seventies the Limits to Growth report (Club of Rome) played a similar catalytic role. The effects of new information reflect the basic uncertainties underlying many environmental issues. These uncertainties diminish only gradually in the course of time, as more and more information becomes available from experience and research.

Copyright in the Information Society: Scenario's and Strategies

Copyright law trades off the costs of limiting access to information against the benefits of providing incentives to create information in the first place. The development of digital rights management (DRM) may disturb the balance between creation and distribution of information. What policy strategy should be followed by a national government given that effective systems of DRM may develop and given that legislation and policy-making increasingly take place at the level of the European Union? Because the quality of the protection that can be obtained by DRM is uncertain, two scenarios are developed. The scenarios require different policy reactions. Alternative policy strategies are discussed.

Private support and social securityPrivate support and social security

Abstract. The issue is addressed whether assistance to persons in need can be left to the ‘family’ and the ‘community’. In that case people depend on their social networks. The support a person receives through a given network of social ties is examined. However, ties are diverse and subject to change. By means of a model of the dynamics of social ties, the conditions for adequate private support are analyzed. The sustainability of private support over time is examined by incorporating the impact on social ties of lending and receiving support. It is shown that support is only an effective alternative in a limited number of situations.

Errors in Judicial Decisions

In criminal cases the task of the judge is to transform the uncertainty about the facts into the certainty of the verdict. In this experiment we examine the relationship between evidence of which the strength is known, subjective probability of guilt and verdict for abstract cases. We look at two situations: (1) all evidence is given and (2) evidence can be acquired. Roughly half of the participants do not base their decision on a subjective belief of the probability of guilt. The others underestimate in general the probability of guilt, but this is more than compensated by a tendency to convict at too low probability of guilt. In the situation where evidence can be acquired, participants do not acquire enough evidence.