Modelling the implied probability of stock market movements

In this paper we study risk-neutral densities (RNDs) for the German stock market. The use of option prices allows us to quantify the risk-neutral probabilities of various levels of the DAX index. For the period from December 1995 to November 2001, we implement the mixture of log-normals model and a volatility-smoothing method. We discuss the time series behaviour of the implied PDFs and we examine the relations between the moments and observable factors such as macroeconomic variables, the US stock markets and credit risk. We find that the risk-neutral densities exhibit pronounced negative skewness. Our second main observation is a significant spillover of volatility, as the implied volatility and kurtosis of the DAX RND are mostly driven by the volatility of US stock prices. JEL Classification: C22, C51, G13, G15Option prices, risk-neutral density, spillover, Volatility

Competition and Relational Contracts: The Role of Unemployment as a Disciplinary Device

When unemployment prevails, relations with a particular firm are valuable for workers. As a consequence, a worker may adhere to an implicit agreement to provide high effort, even when performance is not third-party enforceable. But can implicit agreements – or relational contracts – also motivate high worker performance when the labor market is tight? We examine this question by implementing an experimental market in which there is an excess demand for labor and the performance of workers is not third-party enforceable. We show that relational contracts emerge in which firms reward performing workers with wages that exceed the going market rate. This motivates workers to provide high effort, even though they could shirk and switch firms. Our results thus suggest that unemployment is not a necessary device to motivate workers. We also discuss how market conditions affect relational contracting by comparing identical labor markets with excess supply and excess demand for labor. Long-term relationships turn out to be less frequent when there is excess demand for labor compared to a market characterized by unemployment. Surprisingly though, this does not compromise market performance.relational contracts, involuntary unemployment

A Parallel High-Order Fictitious Domain Approach for Biomechanical Applications

The focus of this contribution is on the parallelization of the Finite Cell Method (FCM) applied for biomechanical simulations of human femur bones. The FCM is a high-order fictitious domain method that combines the simplicity of Cartesian grids with the beneficial properties of hierarchical approximation bases of higher order for an increased accuracy and reliablility of the simulation model. A pre-computation scheme for the numerically expensive parts of the finite cell model is presented that shifts a significant part of the analysis update to a setup phase of the simulation, thus increasing the update rate of linear analyses with time-varying geometry properties to a range that even allows user interactive simulations of high quality. Paralellization of both parts, the pre-computation of the model stiffness and the update phase of the simulation is simplified due to a simple and undeformed cell structure of the computation domain. A shared memory parallelized implementation of the method is presented and its performance is tested for a biomedical application of clinical relevance to demonstrate the applicability of the presented method

Uncertainty quantification for personalized analyses of human proximal femurs

Computational models for the personalized analysis of human femurs contain uncertainties in bone material properties and loads, which affect the simulation results. To quantify the influence we developed a probabilistic framework based on polynomial chaos (PC) that propagates stochastic input variables through any computational model. We considered a stochastic E-ρ relationship and a stochastic hip contact force, representing realistic variability of experimental data. Their influence on the prediction of principal strains (ϵ1 and ϵ3) was quantified for one human proximal femur, including sensitivity and reliability analysis. Large variabilities in the principal strain predictions were found in the cortical shell of the femoral neck, with coefficients of variation of Math Eq. Between 60-80% of the variance in ϵ1 and ϵ3 are attributable to the uncertainty in the E-ρ relationship, while Math Eq are caused by the load magnitude and 5-30% by the load direction. Principal strain directions were unaffected by material and loading uncertainties. The antero-superior and medial inferior sides of the neck exhibited the largest probabilities for tensile and compression failure, however all were very small (Math Eq). In summary, uncertainty quantification with PC has been demonstrated to efficiently and accurately describe the influence of very different stochastic inputs, which increases the credibility and explanatory power of personalized analyses of human proximal femurs

The Fragility of Short-Term Secured Funding Markets

This paper develops an infinite-horizon model of financial institutions that borrow short-term and invest in long-term assets that can be traded in frictionless markets. Because these financial intermediaries perform maturity transformation, they are subject to potential runs. We derive distinct liquidity, collateral, and asset liquidation constraints, which determine whether a run can occur as a result of changing market expectations. We show that the extent to which borrowers can ward off an individual run depends on whether it has sufficient liquidity, collateral, and asset liquidation capacity. These determinants depend on the borrower’s (endogenous) balance sheet and on (exogenous) fundamentals. Systemic runs are possible if shocks to the valuation of collateral held by outside investors are sufficiently strong and uniform, and if the system as a whole is exposed to high short-term funding risk. The theory has policy implications for prudential regulation and lender-of-last-resort interventions

Infrastructure-Based Versus Service-Based : Competition In Telecommunications

Unbundling of the local loop (ULL) has seen quite different "success stories" in the various countries across Europe. Although the obligation for the provision of ULL was implemented in the regulatory framework early and mostly parallel to other means of liberalisation, national implementation has been rather heterogeneous. One question of decisive importance for national regulatory authorities (NRAs) was whether to foster service-based competition in the first phase of liberalisation or to focus on infrastructurebased competition. The different NRAs chose to head down different roads. This paper analyses whether the strategy of NRAs has had any mid-term effect on the economic welfare created in the communications markets. It indicates that infrastructure-based competition has a positive effect on innovation. Moreover, infrastructure-based competition appears to be more important for business customers than for residential clients. On the other hand, service-based competition lowers call prices and appears to be more important to residential markets. The results of this study point out the importance of a balanced approach to both types of policies.competition; telecommunication; ladder of infrastructure; ladder of investement; regulatory policies