Contributions in Merlin

The paper evaluates the German health care reform of 1997, using the individual number of doctor visits as outcome measure and data from the German Socio- Economic Panel for the years 1995-1999. A number of modified count data models allow to estimate the effect of the reform in different parts of the distribution. The overall effect of the reform was a 10 percent reduction in the number of doctor visits. The effect was much larger in the lower part of the distribution than in the upper part.

This work gives a brief overview of the portfolio selection problem following the mean-risk approach first proposed by Markowitz (1952). We consider various risk measures, i.e. variance, value-at-risk and expected-shortfall and we study the efficient frontiers obtained by solving the portfolio selection problem under these measures. We show that under the assumption that returns are normally distributed, the efficient frontiers obtained by taking value-at-risk or expected-shortfall are subsets of the mean-variance efficient frontier. We generalize this result for all risk measures that can be written as a particular combination of mean and variance and we show that for these measures Tobin separation holds under some restrictions.

This paper presents an application of evolutionary portfolio theory to stocks listed in the Swiss Market Index (SMI). We study numerically the long-run outcome of the competition of rebalancing rules for market shares in a stock market with actual dividends taken from firms listed in the SMI. Returns are endogenous because prices are determined by supply and demand stemming from the rebalancing rules. Our simulations show that in competition with rebalancing rules derived from Mean-Variance Optimization, Maximum Growth Theory and Behavioral Finance, the evolutionary portfolio rule discovered in Hens and Schenk-Hoppé (2001) will eventually hold total market wealth. According to this simple rule the portfolio weights should be proportional to the expected relative dividends of the assets.

This paper reports the results of a series of competitive labour market experiments in which subjects have the possibility to reciprocate favours. In the high stake condition subjects earned between two and three times their monthly income during the experiment. In the normal stake condition the stake level was reduced by a factor of ten. We observe that both in the high and the normal stake condition fairness concerns are strong enough to outweigh competitive forces and give rise to non-competitive wages. There is also no evidence that effort behaviour becomes generally more selfish at higher stake levels. Therefore, our results suggest that, contrary to common beliefs, fairness concerns may play an important role even at relatively high stake levels.

"Recent evidence highlights the importance of social norms in many economic relations. However, many of these relationships are long-term and provide repeated game incentives for performance. We experimentally investigate interaction effects of reciprocity and repeated game incentives in two treatments (one-shot and repeated) of a gift-exchange game. In both treatments we observe reciprocity, which is strengthened in the repeated game. A detailed analysis shows that in the repeated game some subjects imitate reciprocity. Thus, reciprocity and repeated game incentives reinforce each other. Observed behaviour is robust against experience. We conclude that a long-term interaction is a “reciprocity-compatible” contract enforcement device."

Preise, Einkommen, und Nachfrage – die zentralen zu erklaerenden Variablen in den Wirtschaftswissenschaften sind objektiv messbar. Daneben gibt es jedoch zwei nicht minder zentrale Groessen, Erwartungen und Praeferenzen, die sich einer direkten objektiven Messung entziehen. Es sind subjektive Variablen, also solche, die von persoenlichen Meinungen und Erfahrungen bestimmt sind. Allerdings bedeutet dies nicht, dass sie ueberhaupt nicht messbar waeren. Ganz im Gegenteil enthalten typische Haushaltsbefragungen eine ganze Reihe von subjektiven Fragen, die ueber verschiedene Aspekte von Erwartungs- und Praeferenzbildung informieren. Im folgenden werde ich darstellen, welche Arten von subjektiven Variablen bisher in der empirischen Wirtschaftsforschung betrachtet wurden. Dann werde ich auf Probleme bei der Interpretation von subjektiven Variablen eingehen. Und schliesslich werde ich die wesentlichen Aspekte der oekonometrischen Modellbildung besprechen und zwei neue Modelle vorstellen.

This paper investigates if multinationals in.uence the political process through lobbying more effectively than national firms. First, I introduce a model which contrasts a multinational’s incentives for lobbying with those of a national firm. Then the effect of lobbying on the political decision is analyzed. I conclude that multinationals have smaller incentives to lobby because they have smaller stakes in national markets. But the effectiveness of lobbying by multinationals might be higher if the government cares much about production in the home country. The resulting regulation depends on the relative strength of these effects.

Economics and psychology are both sciences of human behaviour. This paper gives a survey of their interaction. First, the changing relationship between the two sciences isndiscussed: while economics was once imperialistic, it has become a science inspired by psychological insights. In order to illustrate this, recent developments and evidence for three major areas are presented: bounded rationality, non-selfish behaviour, and the economics of happiness.

"The potential duration of benefits is generally viewed as an important determinant of unemployment duration. This paper evaluates a unique policy change that prolonged entitlement to regular unemployment benefits from 30 weeks to a maximum of 209 weeks for elderly individuals in certain regions of Austria. In the evaluation, we explicitly account for the fact that the program was an endogenous policy response to a crisis affecting individuals with severe labor market problems. The main results are: (i) REBP reduced the transition rate to jobs by 17 ; (ii) accounting for endogenous policy adoption is important and quantitatively significant."

In this chapter we provide a selective survey of experiments to investigate the potential of social motivations in explaining labour market phenomena. We argue that laboratory experiments are a useful instrument to explore issues in labour market theory and personnel economics. Our starting point is the observation that employment relations are frequently governed by incomplete contracts. We show that the norm of reciprocity that leads to gift exchanges is an effective contract enforcement device under conditions of contractual incompleteness. We then present evidence that gift exchange can explain various labour market phenomena that are puzzles from the viewpoint of standard economic theory. Further issues in the related field of personnel economics that have by now been subjected to an experimental scrutiny concern characteristics of the employment relation and the issues of motivation and incentives systems.