Contributions published at Department of Economics (Florian Scheuer)

Innerhalb der Kontrakttheorie hat sich im vergangenen Jahrzehnt die Theorie unvollständiger Verträge als besonders fruchtbar erwiesen. Jüngste Forschungsarbeiten zeigen jedoch, daß die durch Hart und Moore (1988) als gegeben geglaubte Fundierung nicht sehr robust ist. Ziel des Artikels ist es, einen Einblick in aktuelle Fragen und Ergebnisse der diesbezüglichen Forschung zu ermöglichen.

The retirement decisions of spouses may be interdependent for various reasons: similarity of tastes, joint assets, sharing rules for income and housework, or complementarity of leisure. Because of data limitations, only a few empirical studies exist on this topic. From a policy point of view interdependent retirement could become important if legislators in different EC countries are forced to synchronize minimum retirement ages, which are lower now for females than males in a number of countries. In the theoretical part, the reaction of spouses to changes in the retirement age of their partners is analysed for typical family patterns. In the empirical part, the possibility of interdependent retirement is studied for Austrian data. The findings show an asymmetry: husbands react to changes in wives' legal minimum retirement age, wives don't react vice versa. The cross effect on men's participation rates -- resulting from a rise in women's minimum retirement age --is almost half as big as the first-round effect upon the women themselves.

Because of the public good character of global emissions it is difficult to implement reduction targets as formulated at Toronto or Rio. This paper presents a simple mechanism for inducing efficient contributions to the reductions of emissions as a non-cooperative equilibrium. The world is partitioned into groups of countries, and then each country is taxed or subsidised according to its relative performance in the group. We estimate abatement cost- and benefit functions for 135 countries and simulate the mechanism for different groupings of countries. The simulations show that the involved global budget is the smaller the finer the partition and the more equal the countries within a group. Moreover, with such a partition most countries profit from the mechanism so that broad political support may be expected. If groups are composed of unequal countries, then the mechanism leads to a more egalitarian distribution of world income and welfare.

This paper employs ICP expenditure data to investigate the relationship between income and product diversity. It turns out that per-capita income has a strong positive impact on the number of products consumed at a non-negligible level in a country, and a significant negative impact on the concentration of consumers' expenditure across different goods categories. Inequality in the size distribution of incomes has a significant positive impact on the number of consumed goods, but no clear effect on the concentration of expenditure.

This study shows that in general the impact of equity on tax evasion depends on how the taxpayer's risk aversion is affected by perceived equity. Then possible reasons are discussed why an increase in perceived equity may increase a person's risk aversion and thus lead to a decrease of evasion. An economic as well as a psychological argument are presented which can explain a positive relationship between risk aversion and equity, and thus, between evasion and inequity. The economic argument considers cases where the valuation of public output increases with income. The psychological argument is based on the hypothesis that people find evasion more blameworthy in a system which is considered to be just than in an unfair system. With such a norm an increase in equity increases the bad reputation or bad conscience of evaders and leads to a reduction of evasion.

This study starts from the observation that today's Western trading nations are exposed to multiple risks of energy supplies, eg simultaneous shortage of oil and gas supplies. To cope with these risks, both oil and gas can be stockpiled. Adopting the viewpoint of a policy maker who aims at minimizing the expected cost of security of supply, optimal simultaneous adjustments of oil and gas stocks to exogenous changes such as an increase in the probability of supply disruption are derived. Against this benchmark, one-dimensional rules such as ‘oil reserves for 90 days’ turn out to be not only suboptimal but also to suggest adjustments exacerbating suboptimality.

This paper purports to analyze a hospital's adoption of both product and process innovation as a quantal choice. The impacts of this decision on physicians, while depending on institutions that differ between the US and continental Europe, are shown to feed back to the hospital, influencing the profitability of the innovation. Recent changes of hospital finance give rise to testable comparative predictions in both institutional settings.

We use data from the German Socio-Economic Panel to investigate how individual happiness is affected by unemployment. Unemployment has a large and negative effect even after controlling for individual specific fixed effects. Nonparticipation, in contrast, is much less harmful to happiness. Further, we decompose the total well-being costs of unemployment and find that well above three quarters are non-pecuniary, and below one quarter pecuniary. One implication is that income support programs for the unemployed do very little at mitigating the adverse effects of unemployment, and such transfers are unlikely to generate unemployment.

This paper explores the relation between non-exponential waiting times between events and the distribution of the number of events in a fixed time interval. It is shown that within this framework the frequently observed phenomenon of overdispersion, i.e. a variance that exceeds the mean, is caused by a decreasing hazard function of the waiting times, while an increasing hazard function leads to underdispersion. Using the assumption of i.i.d. gamma distributed waiting times, a new count data model is derived. Its use is illustrated in two applications: the number of births, and the number of doctor consultations.

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This article studies several attributes of a firm's long-run decisions about organizational structure, attributes that affect the firm's short-run innovative activity. We focus on flexibility, which lowers the future costs of implementing innovations, and research capabilities, which improve the future opportunities for innovation. We consider two dimensions of innovation: demand-enhancing (product) and cost-reducing (process). These two types of innovation are complementary in terms of increasing the firm's net revenue in the short run. The complementarities between the firm's short-run decision variables then lead to complementarities between its long-run decisions about product and process flexibility and research capabilities.

In current welfare state analysis there is little theory to explain the action of exclusive groups. This article explores the possibilities of a theory that focuses on the interaction between individual choices and strategies, the formal systems, policies and rules of governments and the informal norms and practices of groups. The argument is that club theory, a branch of public choice concepts, represents a promising new element in such an approach. A theoretical frame has to account for both collectivisation and fragmentation processes - how mass solidarities in welfare states come to be created and in turn to be broken up into narrower mutualities. Migration is used as an example to show how the actions of migrants and policy decisions about them affect these dynamics or are affected by them.

The paper develops an endogenous growth model which is based on lexicographical consumer preferences. The central variable determining the long-run rate of growth is personal income distribution. Its role in the process of growth depends crucially on the assumption about productivity growth. If productivity grows proportionally to product diversity, then an unequal distribution of incomes, measured by the rate of proportion of top to average incomes, has a positive effect on growth. However, under alternative assumptions, for instance, if productivity is a function of average income, inequality turns out to be harmful for economic growth.

Key demographic variables, such as the number of children and the number of marriages or divorces, can only take integer values. This papers deals with the estimation of single equation models in which the counts are regressed on a set of observed individual characteristics such as age, gender, or nationality. Most empirical work in population economics has neglected the fact that the dependent variable is a nonnegative integer. In the few cases where this feature was recognized, the authors advocated the use of the Poisson regression model. The Poisson model imposes, however, the equality of conditional mean and variance, a restriction which is often rejected by the data. We propose a generalized event count model to simultaneously allow for a wide class of count data models and account for over- and underdispersion. This model is successfully applied to German data on fertility, divorces and mobility.

The study introduces a distinction between two types of labor mobility: direct job to job changes (which are assumed to be voluntary) and job changes after experiencing an unemployment spell (assumed to be involuntary). Exploiting the close relationship between those two phenomena we adopt a bivariate regression framework for our empirical analysis of data on male individuals in the German labor market. To account for the non-negative and discrete nature of the two counts of job changes in a ten year interval a new econometric model is proposed: the bivariate Poisson regression proves to be superior to the univariate specification. Further, the empirical content of distinguishing between two types of mobility is subject to a test, and, in fact, supported by the data: The hypothesis that both measures are observationally equivalent can be rejected.