Die Gesundheitsausgaben steigen seit langem zügig, und alle Versuche der Politik, dies zu dämpfen, erscheinen mehr oder
weniger erfolglos. Der Gesundheitsökonom Peter Zweifel legt dar, wie die grundlegenden Kräfte bei der Entwicklung
des Gesundheitssektors wirken, welche Rolle Bundes- und Kantonspolitiker spielen können und wie sich die Konflikte
zwischen Bürgern und Politikern in jüngerer Zeit verschärft haben.
This contribution shows that for certain classes of insurance risks, pricing can be based on expected values under a probability measure P* amounting to quasi risk-neutral pricing. This probability measure is unique and optimal in the sense of minimizing the relative entropy with respect to the actuarial probability measure P, which is a common approach in the case of incomplete markets. After expounding the key elements of this theory, an application to a set of industrial property risks is developed, assuming that the severity of losses can be modeled by 'Swiss Re Exposure Curves', as discussed by Bernegger (1997). These curves belong to a parametric family of distribution functions commonly used by pricing actuaries. The quasi risk-neutral pricing approach not only yields risk exposure specific premiums but also Risk Adjusted Capital (RAC) values on the very same level of granularity. By way of contrast, the conventional determination of RAC is typically considered on a portfolio level only.
This article investigates power and size of some tests for exogeneity of a binary explanatory variable in count models by conducting extensive Monte Carlo simulations. The tests under consideration are Hausman contrast tests as well
as univariate Wald tests, including a new test of notably easy implementation.
Performance of the tests is explored under misspecification of the underlying model and under different conditions regarding the instruments. The results indicate that
often the tests that are simpler to estimate outperform tests that are more demanding.
This is especially the case for the new test.
This paper derives a central bank's optimal liquidity supply towards a money market with an unrestricted lending facility. We show that when the effect of liquidity on market rates is not too small, and the monetary authority cares for both interest rates and liquidity conditions, then the optimal allotment policy may entail a discontinuous
reaction to initial conditions. In particular, the model predicts a threshold level of liquidity below which the central bank will not bail out the banking system. An
estimation of the liquidity effect for the euro area suggests that the discontinuity might have contributed to the Eurosystem's tight response to occurrences of underbidding during the period June 2000 through March 2004.
The annual Ottobeuren Seminar on Economics brings together experts on a previously chosen subject. The special purpose of these seminars is to present new theoretical approaches as well as new empirical findings and to discuss the political-economic conclusions with them. This volume contains the papers and discussions of the 38th Ottobeuren Seminar on Economics dealing with the subject of experimental economics. It presents several experiments, some of whose results clearly contradict the predictions of traditional economics and thus provide important incentives for a reformulation of the theoretical approaches.
We consider a two-stage game with cost-reducing investments followed by a linear differentiated Cournot duopoly. With competition inversely parameterized by the extent of product differentiation, investment in the subgame perfect equilibrium is typically minimal for intermediate levels of competition. Laboratory experiments partly confirm the U-shape in a reduced one-stage version of the game. In the two-stage version, there is no evidence for positive effects of moving from intermediate to intense competition.
The goal of dynamic causal modelling (DCM) of neuroimaging data is to study experimentally induced changes in functional integration among brain regions. This requires (i) biophysically plausible and physiologically interpretable models of neuronal network dynamics that can predict distributed brain responses to experimental stimuli and (ii) efficient statistical methods for parameter estimation and model comparison. These two key components of DCM have been the focus of more than thirty methodological articles since the seminal work of Friston and colleagues published in 2003.
In this paper, we provide a critical review of the current state-of-the-art of DCM. We inspect the properties of DCM in relation to the most common neuroimaging modalities (fMRI and EEG/MEG) and the specificity of inference on neural systems that can be made from these data. We then discuss both the plausibility of the underlying biophysical models and the robustness of the statistical inversion techniques. Finally, we discuss potential extensions of the current DCM framework, such as stochastic DCMs, plastic DCMs and field DCMs.
Schizophrenia is associated with fronto-temporal dysconnectivity, but it is not clear whether this is a risk factor for the disorder or is a consequence of the established illness. The aim of the present study was to use fMRI to investigate fronto-temporal connectivity in subjects with prodromal signs of schizophrenia using the Hayling Sentence Completion Task (HSCT). Thirty participants, 15 with an at risk mental state (ARMS) and 15 healthy controls were scanned whilst completing 80 sentence stems. The congruency and constraint of sentences varied across trials. Dynamic causal modelling (DCM) and Bayesian model selection (BMS) were used to compare alternative models of connectivity in a task related network. During the HSCT ARMS subjects did not differ from Healthy Controls in terms of fronto-temporal activation, i.e. there was neither a main effect of group nor a group-by-task interaction. However, there was both a significant main effect of group and a significant interaction in the anterior cingulate cortex (ACC), with greater ACC activity in the ARMS subjects. A systematic BMS procedure among 14 alternative DCMs including the ACC, middle frontal, and middle temporal gyri revealed intact task-dependent modulation of fronto-temporal effective connectivity in the ARMS group. However, ARMS subjects showed increased endogenous connection strength between the ACC and the middle temporal gyrus relative to healthy controls. Although task related fronto-temporal integration in the ARMS was intact, this may depend on increased engagement of the ACC which was not observed in healthy control subjects.
A standard method to elicit certainty equivalents is the Becker-DeGroot-Marschak (BDM) procedure. We compare the standard BDM procedure and a BDM procedure with a restricted range of minimum selling prices that an individual can state. We find that elicited prices are systematically affected by the range of feasible minimum selling prices. Expected utility theory cannot explain these results. Non-expected utility theories can only explain the results if subjects consider compound lotteries generated by the BDM procedure. We present an alternative explanation where subjectsnsequentially compare the lottery to monetary amounts in order to determine theirnminimum selling price. The model offers a formal explanation for range effects and for the underweighting of small and the overweighting of large probabilities.
