Publikationenhttps://oparu.uni-ulm.de/xmlui/handle/123456789/52020-02-17T23:25:40Z2020-02-17T23:25:40ZInfinitely divisible and related distributions and Lévy driven stochastic partial differential equationsBerger, Davidhttps://oparu.uni-ulm.de/xmlui/handle/123456789/253492020-02-17T19:04:54Z2020-02-17T00:00:00ZInfinitely divisible and related distributions and Lévy driven stochastic partial differential equations
Berger, David
This thesis deals with different topics in probability theory. We are interested in infinitely divisible distributions and their densities, the class of quasi-infinitely divisible distributions and Lévy driven stochastic partial differential equations.
In Chapter 2 we deal with infinitely divisible distributions and their densities. We obtain bounds of the integral modulus of continuity in terms of the characteristic triplet. We then apply our results to stochastic integrals.
In Chapter 3 we study the class of probability measures \mu(dx)=\mu_{ld}(dx)+\mu_{ac}(dx), where \mu_{ld} is a discrete lattice distribution and \mu_{ac} is absolutely continuous. We prove that if \hat{\mu}_{ld}(z)\neq 0 for all z\in R then \mu is quasi-infinitely divisible if and only if \hat{\mu}(z)\neq 0 for all z\in R. As an application of this result we study certain variance mixtures and prove that they are quasi-infinitely divisible.
In Chapter 4 we give sufficient conditions for the existence of a generalized solution s in the space of distributions of the stochastic partial differential equation p(D)s=q(D)\dot{L}, where p and q are polynomials in C^d and \dot{L} is a so called Lévy white noise. Furthermore, we give sufficient conditions for the existence of a mild solution and provide a sufficient condition when the mild solution can be identified with a generalized solution.
Chapter 5 deals with linear and semilinear Lévy driven stochastic partial differential equations. In the linear case we work with different distributional spaces and show existence and uniqueness results under different assumptions. As a next step we analyze a semilinear partial differential equation driven by Lévy white noise in weighted Besov spaces.
In Chapter 6 we prove central limit theorems for the sample mean and autocovariance of a moving average random field. We use a sampling scheme on a grid, which can be deterministic or random.
2020-02-17T00:00:00ZEssays on cooperative behavior and the impact of information on self-assessments and performanceKleinknecht, Janinahttps://oparu.uni-ulm.de/xmlui/handle/123456789/244362020-01-27T05:53:34Z2020-01-23T00:00:00ZEssays on cooperative behavior and the impact of information on self-assessments and performance
Kleinknecht, Janina
Promises and expectations play an important role in strategic environments, since cooperation often requires individuals to rely on informal commitments. Indeed, numerous experiments have already shown that promises are more than cheap talk. The motives for promise keeping can be rooted in social preferences, which have been demonstrated to differ for men and women. This paper systematically investigates gender differences in promise keeping based on the experimental design of Vanberg (2008). In particular, I analyze gender differences in the motives for promise keeping and the understanding of promises. Moreover, I compare the behavior of men and women in mixed and single gender interactions. I find no gender differences in the likelihood of giving promises, but promises raise expectations of women more than those of men. Women keep promises more often than men, although both, men and women, anticipate that a promise raises expectations on the part of its receiver. Moreover, the experiment reveals that there are no gender differences in the underlying motives for promise keeping. For men and women both, their own promise as well as the expectations of the receiver, matter.; In a laboratory experiment, we investigate whether individuals incorporate social information about their peers in their relative self-assessments. In particular, we compare the effectiveness of three different types of social information: subjects either learn their peers (i) average absolute performance, (ii) average self-assessment or (iii) average extent of miscalibration. Moreover, we explore whether subjects demand social information and which type of social information they prefer. Our results suggest that social information can help debiasing subjects' self-assessments, but not all types of information are equally effective. In our experiment, only learning about the average miscalibration of others makes self-assessments more accurate. Subjects are, in general, willing to pay for social information, but mostly prefer information about others' absolute performance which is least helpful. Consequently, endogenous choice of social information does not further help to improve self-assessments.; Current research on (managerial) turnover mainly focuses on performance changes and is ambiguous with respect to the results. Yet, the literature agrees that short-term performance changes are induced by opposing effects. Specifically, a turnover leads to an information loss that might influence the staffing of positions negatively and incentives to exhibit effort positively. In order to identify the predominant effect
and how it affects overall short-term performance, we employ a unique measure of effort and different degrees of information loss. Therefore, we analyse within-season coach turnovers of professional soccer teams in the German Bundesliga, using a generalized version of the synthetic ontrol method. In order to take into account low and high information loss, we differentiate between insider and outsider successors. Insiders might staff positions better while outsiders might be able to elicit higher effort. Our results are in line with these expectations: a turnover leads to an increase in players’ effort, but only in case of an outsider coach, both, insider and outsider, improve performance.
2020-01-23T00:00:00ZTheoretical and empirical essays on the differential effects of information on microeconomic decision makingWürtenberger, Danielhttps://oparu.uni-ulm.de/xmlui/handle/123456789/230692019-12-16T10:25:36Z2019-12-12T00:00:00ZTheoretical and empirical essays on the differential effects of information on microeconomic decision making
Würtenberger, Daniel
Index-Based Insurance in Developing Countries: Rational Neglect?
Microinsurance adoption in developing countries is low, despite its potential
to foster economic growth. Recent research is not able to explain
the low take-up rates within the neoclassical framework. I contribute
to this stream of research by proposing rational as well as boundedly rational
explanations for the low attractiveness of microinsurance within
a stochastic framework. More precisely, I analyse weather index insurance
that guarantees farmers an indemnity payment contingent on
the realized rainfall at the nearest weather station. My model makes
separate predictions for close farmers, whose location is near a weather
station, and distant farmers. Results show that the latter ask for less
than 50% insurance coverage even under perfect rationality. I extend
the model by integrating two possible cognitive biases that reflect a
lack of trust and a lack of knowledge about the insurance. I can show
that a lack of trust reduces insurance demand most for close farmers,
while a lack of understanding negatively affects the demand of distant
farmers. Moreover, subsidies are more effective for close than for
distant farmers.; Loss aversion and the demand for index insurance: This work analyzes if reference dependence and loss aversion can explain
the puzzling low adoption rates of rainfall index insurance. We
present a model that predicts the impact of loss aversion on index insurance
demand to vary with different levels of insurance understanding.
Index insurance demand of farmers who are unaware of the loss-hedging
benefit that insurance provides decreases with loss aversion. In contrast,
insurance demand of farmers who are aware of the loss-hedging
benefit increases with loss aversion. The model further predicts that
farmers who are unaware of the loss-hedging benefit will not demand
an even highly subsidized index insurance. Using data from a randomized
controlled trial involving a sample of Indian farmers we provide
empirical support for our core conjecture that insurance understanding
mitigates the negative impact of loss aversion on index insurance
adoption.; Managerial Turnover - Effects on Performance and Effort: Managerial turnover leads to an information loss that might influence the staffing of
positions negatively and affects effort provision positively. In order to identify how
this affects short-term performance, we analyze within-season coach turnovers in
professional soccer, using a generalized version of the synthetic control method. In
order to take into account low and high information loss, we differentiate between
insider and outsider successors and employ a unique measure of effort. Our results
suggest that a turnover leads to an increase in players’ effort, but only in case of
an outsider successor, both, insider and outsider, improve performance.
2019-12-12T00:00:00ZConductors of superelliptic curvesKohls, Romanhttps://oparu.uni-ulm.de/xmlui/handle/123456789/226972019-12-09T12:24:24Z2019-11-28T00:00:00ZConductors of superelliptic curves
Kohls, Roman
The main object of this thesis are conductors associated to algebraic curves. For a superelliptic curve given by y^n=g(x) we give a decomposition of the conductor exponent at primes p not dividing n in n-1 terms such that the wild part of each term is independent of n and given in terms of the polynomial g. Based on this decomposition, we obtain an upper bound for the conductor exponent in terms of g and n. We provide examples showing that this bound is sharp. As an application to the proven inequalities, we prove that the conductor exponent of a Picard curve at primes not equal to 2 or 3 is bounded by the valuation of a minimal discriminant of the curve.
2019-11-28T00:00:00Z