Charity hazard - A real hazard to natural disaster insurance

After the flooding in 2002 European governments provided billions of Euros of financial assistance to their citizens. Although there is no doubt that solidarity and some sort of assistance is reasonable, the question arises why these damages were not sufficiently insured. One explanation why individuals reject to obtain insurance cover against natural hazards is that they anticipate governmental and private aid. This problem became to be known as "charity hazard". The present paper gives an economic analysis of the institutional arrangements on the market for natural disaster insurances focusing on imperfections caused by governmental financial relief. It provides a theoretical explanation why charity hazard is a problem on the market for natural disaster insurances, in the way that it acts as an obstacle for the proper diffusion and therefore the establishment of natural hazard insurances. This paper provides a review of the scientific discussion on charity hazard, provides a theoretical analysis and points out the existing empirical problems regarding this issue.natural hazard insurance, market failure, governmental assistance

Trip-Based Public Transit Routing

We study the problem of computing all Pareto-optimal journeys in a public transit network regarding the two criteria of arrival time and number of transfers taken. We take a novel approach, focusing on trips and transfers between them, allowing fine-grained modeling. Our experiments on the metropolitan network of London show that the algorithm computes full 24-hour profiles in 70 ms after a preprocessing phase of 30 s, allowing fast queries in dynamic scenarios.Comment: Minor corrections, no substantial changes. To be presented at ESA 201

Gerbil: A Fast and Memory-Efficient kk-mer Counter with GPU-Support

A basic task in bioinformatics is the counting of $k$-mers in genome strings. The $k$-mer counting problem is to build a histogram of all substrings of length $k$ in a given genome sequence. We present the open source $k$-mer counting software Gerbil that has been designed for the efficient counting of $k$-mers for $k\geq32$. Given the technology trend towards long reads of next-generation sequencers, support for large $k$ becomes increasingly important. While existing $k$-mer counting tools suffer from excessive memory resource consumption or degrading performance for large $k$, Gerbil is able to efficiently support large $k$ without much loss of performance. Our software implements a two-disk approach. In the first step, DNA reads are loaded from disk and distributed to temporary files that are stored at a working disk. In a second step, the temporary files are read again, split into $k$-mers and counted via a hash table approach. In addition, Gerbil can optionally use GPUs to accelerate the counting step. For large $k$, we outperform state-of-the-art open source $k$-mer counting tools for large genome data sets.Comment: A short version of this paper will appear in the proceedings of WABI 201

Who is going to save us now? Bureaucrats, Politicians and Risky Tasks

The paper compares the policy choices regarding risk-transfer against low-probability-high-loss events between elected and appointed public officials. Empirical evidence using data on U.S. municipality-level shows that appointed city managers are more likely to adopt federal risk-transfer regimes. It is argued that the variation in the level of insurance activity emerges from the different incentive schemes each government form is facing. Controlling for spatial dependencies further shows that the participation decision in the insurance program significantly depends on the decision of neighboring communities.Politicians, bureaucrats, decision making under uncertainty, flood insurance, spatial econometrics

Accelerating Wilson Fermion Matrix Inversions by Means of the Stabilized Biconjugate Gradient Algorithm

The stabilized biconjugate gradient algorithm BiCGStab recently presented by van der Vorst is applied to the inversion of the lattice fermion operator in the Wilson formulation of lattice Quantum Chromodynamics. Its computational efficiency is tested in a comparative study against the conjugate gradient and minimal residual methods. Both for quenched gauge configurations at beta= 6.0 and gauge configurations with dynamical fermions at beta=5.4, we find BiCGStab to be superior to the other methods. BiCGStab turns out to be particularly useful in the chiral regime of small quark masses.Comment: 25 pages, WUB 94-1

The Sub-Saharan Water Crisis: An Analysis of its Impact on Public Health in Urban and Rural Nigeria

Today, 11% of the global population still lacks access to clean water, one of humans’ most basic needs. Those who lack a safe water source are largely concentrated in sub-Saharan Africa, where only 61% have access to safe water. Within this region, large disparities exist that hide the severity of the problem for some communities. The term “water crisis” is often used to describe the lack of water access throughout the world and the resulting consequences. In this thesis, the impact the water crisis has on public health in sub-Saharan Africa was analyzed using Nigeria as a model nation. Specific forces that contribute to the persistence of the water crisis and the public health outcomes were examined. Urban and rural Nigeria were researched separately, as each setting has its own set of obstacles concerning the water crisis and its own set of public health issues. It was found that in both urban and rural Nigeria, the increased transmission of water-related diseases was a significant burden caused by the water crisis. In Lagos, a city in southern Nigeria, the poor environmental conditions allow for the spreading of diseases through the fecal-oral route of transmission. Additionally, diseases that are typically found in rural setting are becoming more prevalent in Lagos due to the unkempt environment. In rural Nigeria, the lack of safe water sources makes the chances of contracting waterborne diseases very high. The control of water-related diseases is made worse in rural areas because it is difficult to get resources to an isolated rural area. This problem is exacerbated in places suffering from ongoing conflict. However, the prevalence of several diseases has decreased as the availability of water sources increases. By pointing out the severe public health consequences that the water crisis has on sub-Saharan Africa, the goal of this thesis is to inspire further progress towards water access for all