Publications

In the last decades all over the world pension policy reforms have tried to account for the changing demographic and socio-economic framework. An excellent starting point for economic analyses of reform strategies is the Mirrlees Review which argues that pension policy should simultaneously address pension benefit design and the taxation of pensions. We focus on old-age pension taxation and address policy conflicts which come along with international migration of citizens as employees and pensioners. The widely implemented system of deferred income taxation of pensions benefits generates problems of international tax equity when workers who were exempted from income tax on their old-age pension saving emigrate and receive pension benefits in another country. We argue that it is unlikely to solve these problems in double taxation treaties and propose to amend deferred income taxation with the equivalent system of pre-taxed pension benefits. This amendment seems politically viable, since it keeps two attractive features of deferred income taxation, viz. intertemporal neutrality and preferential taxation in comparison to traditional comprehensive income taxation, but avoids inequitable income tax revenue losses, when pensioners emigrate. In order to achieve international equity among EU member countries we regard a multilaterally coordinated system of pre-taxed pension benefits taxation as a superior strategy to single-country measures or complicated renegotiations of bilateral double taxation treaties.

We show how to extract the expected risk-neutral correlation between risk-neutral distributions of the market index (S&P 500) return and its expected volatility (VIX). Comparing the implied correlation with its realized counterpart reveals a significant index-to-volatility correlation risk premium. It compensates for the fear of enduring negative market returns and measures a new dimension of conditional risk not covered by other variables such as the variance risk premium or skewness. Incorporating information from both equity and volatility markets, it predicts future investment opportunities and (conditional as well as unconditional) risk.

This paper investigates how process data like response time and click position relates to economic decisions. We use a social value orientation experiment, which can be considered as a prototypical multi-attribute decision problem. We find that in the social value orientation task more individualistic subjects have shorter response times than prosocial subjects. Individualistic subjects click more often on their own payoffs than on the others’ payoffs, and they click more often on their own payoffs than prosocial subjects. These results show that response times and click positions can be used as indicators of people’s preferences.

We study whether early tracking of students based on ability increases migrant-native achievement gaps. To eliminate confounding impacts of unobserved country traits, we employ a differences-in-differences strategy that exploits international variation in the age of tracking as well as student achievement before and after potential tracking. Based on pooled data from 12 large-scale international student assessments, we show that cross-sectional estimates are likely to be downward-biased. Our differences-in-differences estimates suggest that early tracking does not significantly affect overall migrant-native achievement gaps, but we find evidence for a detrimental impact for less integrated migrants.

We test experimentally whether monitoring is less likely to reduce work motivation in distant than in close principal-agent relationships. Employing the same standard subject pool of students, we compare a laboratory and an internet implementation of an experimental principal-agent game where the principal can impose control at two different levels on the agent. Agency relationships are arguably more distant in the internet than in the laboratory setting. We find that differences in agents' effort due to an increase in the level of control are larger in the internet than in the laboratory experiment. The effect is driven by both higher intrinsic motivation and stronger control aversion in the laboratory. Agents' effort differences are fairly stable over time in both experiments which indicates that even experienced agents react more negatively to the implementation of control in the laboratory than on the internet.

Although understanding preferences for privacy is of great importance to economists, businesses and politicians little is known about the factors that shape the individual willingness to share personal data. This article provides three experimental studies with a total of 470 participants that help characterizing individual preferences for sharing personal data varying the characteristics of potential recipients. We find that participants’ willingness to share personal data with anonymous recipients decreases with the number of recipients. However, social distance to the recipients and the extent of personal data a single recipient receives do not decrease the willingness to share personal data. Further, we provide a methodological insight by showing that verification of personal data is essential when eliciting privacy preferences.

In many social situations, human behaviour differs from the Nash-equilibrium under selfish payoff-maximisation. Numerous social-preference models have been proposed, virtually all of them relying on the Nash-equilibrium concept. This paper determines the Nash-equilibrium sets that result given experiment participants’ elicited preferences, and tests the various aspects of a ‘revealed-preference Nash-equilibrium’ by inducing common knowledge of preferences, using a publicgood situation as an example. The data show that in a three-player public-good situation, multiple equilibria should be expected relatively often (in a third of the cases). Second, most participants’ individual behaviour is in accordance with aspects of Nash equilibrium: most people best-respond to their beliefs, choose equilibrium actions, and consider beliefs that correspond to an equilibrium. However, many participants predict others’ behaviour poorly, which also entails that behaviour rarely is in equilibrium. This points to models like level-k as potential components for better social-preference theories. The experimental findings are obtained using experienced participants and robust to giving participants the option to look up the set of equilibria of their game, and to reducing the number of players to two.

In the current literature, there is a lively debate about whether a level-k model can be based on salience to explain behaviour in games with distinctive action labels such as hide-and-seek or discoordination games. This study presents six different experiments designed to measure salience. When based on any of these empirical salience measures, the standard level-k model does not explain hide-and-seek behaviour. Modifying the model such that players followsalience when payoffs are equal, the model fits hide-and-seek data well. However, neither the original nor the modified model account for data from a discoordination game. This holds true even when basing the level-k prediction on participants’ own individual salience assessments.