infonet-economy

«Risiko Krankenversicherung» beschreibt die soziale und private Krankenversicherung der Schweiz mit statistischen Methoden. Die Verankerung der Autorinnen und Autoren in Wissenschaft und Praxis führt zu einer einzigartigen Mischung aus Analyse und praktischer Erfahrung. Das Buch folgt den aktuellen Fragen zu KVG und VVG: Kostenanstieg, faire Prämienkalkulation, Solvenz, optimaler Risikoausgleich, Entwicklung von Managed Care. Dabei kommen theoretische Konzepte und erfolgreiche Reformen zur Sprache, die z. T. auf die vorangegangenen Auflagen dieses Buches zurückzuführen sind.

There has been a recent interest in reporting p-values adjusted for the resampling-based stepdown multiple testing procedures proposed in Romano and Wolf (2005a,b). The original papers only describe how to carry out multiple testing at a fixed significance level. Computing adjusted p-values instead in an efficient manner is not entirely trivial. Therefore, this paper fills an apparent gap by detailing such an algorithm.

During the 1990s, the social health insurance schemes of Germany, the Netherlands, Switzerland, Belgium and Israel were significantly reformed by the introduction of freedom of choice (open enrolment) of health insurer. This was introduced alongside a system of risk adjustment to compensate health insurers for enrolees with predictable high medical expenses. Despite the similarity in the health insurance reforms in these countries, we find that both the rationale behind these reforms and their impact on consumer choice vary widely.

In this article we seek to explain the observed variation in switching rates by cross-country comparison of the potential determinants of health insurer choice. We conclude that differences in choice setting, and in the net benefits of switching, offer a plausible explanation for the large differences in consumer mobility.

Finally, we discuss the policy implications of our cross-country comparison. We argue that the optimal switching rate crucially depends on the goals of the reforms and the quality of the risk-adjustment system. In view of this, we conclude that switching rates are currently too low in the Netherlands, and an active government policy to encourage consumer mobility seems warranted. In Germany and Switzerland, high switching rates call for an improvement of the rather poor risk-adjustment systems. Given low switching rates in Israel and Belgium, improving risk adjustment is less urgent, but still required in the long run.

Gift-giving customs are ubiquitous in social, political, and business life. Legal regulation and industry guidelines for gifts are often based on the assumption that large gifts have the potential to influence behavior and create confl of interest, but small gifts do not. However, scientific evidence on the impact of small gifts on business relationships is scarce. We conducted a controlled field experiment in collaboration with sales agents of a multinational consumer products company to study the influence of small gifts on the outcome of business negotiations. We find that small gifts matter. On average, sales representatives generate more than twice as much revenue when they distribute a small gift at the onset of their negotiations. However, we also find that small gifts tend to be counterproductive when purchasing and sales agents meet for the first time, underlining that the nature of the business relationship crucially affects the profitability of gifts.

Switzerland introduced managed care options in its social health insurance market in order to contain health care expenditures (HCE). These capitated Managed Care plans reduce costs through gatekeeping, internal guidelines, promoting generic substitution etc. Given the cost benefits of about 62%, the crucial question for both health insurers and the legislator is whether MC plans enhance efficiency or benefit from self-selection. Up to now, only one paper by Lehmann and Zweifel has analysed this question by applying Swiss data (and appropriate econometric tools). Their breakdown of the 62% cost benefit was 40% efficiency gains and 22% selection effect.
Our research applied a matching technique to estimate the efficiency gains. All 55,165 MC pol-icy holders of a given fund, across 18 different MC plans, formed the starting point. The sam-ple was divided into 442 risk classes according to demographics, place of residence, chronic conditions etc. Out of 900,000 insured within the same fund who did not choose MC plans but had identical coverage and free access to providers, we drew “twin samples” of identical size and risk structure as the MC plans (according to the 442 risk classes) and calculated their aver-age HCE. We re-sampled up to 60 times per plan and calculated the average HCE of the 60 averages. This average of averages was compared with the simple average of HCE in the MC plan, yielding the efficiency gain. The same average of averages compared with the simple average of all non-MC policy holders living in the same area indicates the selection effect. All calculations were done separately for each MC plan and two different years (2006 and 2007).
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Our approach reveals efficiency gains of only 8.7% (across all plans) and selection effects of about 52%. However, the different plans vary substantially, and our analysis also identifies a best practice plan with 18.5% efficiency gains. The goal of this study was also to inspire those plans below the benchmark to copy the best practice tools of the leading MC plans.

This paper studies the impact of the presence of human subjects in the role of a seller on bidding in experimental second-price auctions. Overbidding is a robust finding in second- price auctions, and spite among bidders has been advanced as an explanation. If spite extends to the seller, then the absence of human sellers who receive the auction revenue may bias upwards the bidding behavior in existing experimental auctions. We derive the equilibrium bidding function in a model where bidders have preferences regarding both, the payoffs of other bidders and the seller’s revenue. Overbidding is optimal when buyers are spiteful only towards other buyers. However, optimal bids are lower and potentially even truthful when spite extends to the seller. We experimentally test the model predictions by exogenously varying the presence of human subjects in the roles of the seller and competing bidders. We do not detect a systematic effect of the presence of a human seller on overbidding. We conclude that overbidding is not an artefact of the standard experimental implementation of second-price auctions in which human sellers are absent.

Changed reward functions have been proposed as a core feature of stimulant addiction, typically observed as reduced neural responses to non-drug-related rewards. However, it was unclear yet how specific this deficit is for different types of non-drug rewards arising from social and non-social reinforcements. We used functional neuroimaging in cocaine users to investigate explicit social reward as modeled by agreement of music preferences with music experts. In addition, we investigated non-social reward as modeled by winning desired music pieces. The study included 17 chronic cocaine users and 17 matched stimulant-naive healthy controls. Cocaine users, compared with controls, showed blunted neural responses to both social and non-social reward. Activation differences were located in the ventromedial prefrontal cortex overlapping for both reward types and, thus, suggesting a non-specific deficit in the processing of non-drug rewards. Interestingly, in the posterior lateral orbitofrontal cortex, social reward responses of cocaine users decreased with the degree to which they were influenced by social feedback from the experts, a response pattern that was opposite to that observed in healthy controls. The present results suggest that cocaine users likely suffer from a generalized impairment in value representation as well as from an aberrant processing of social feedback.

The ability to generalize previously learned information to novel situations is fundamental for adaptive behavior. However, too wide or too narrow generalization is linked to neuropsychiatric disorders. Previous research suggests that interactions between the dopaminergic system and the hippocampus may play a role in generalization, but whether and how the degree of generalization can be modulated via these pathways is currently unknown. Here, we addressed this question in humans using pharmacology, functional magnetic resonance imaging, and computational modeling. Blocking dopamine D2-receptors (D2R) altered generalization behavior as revealed by an increased kurtosis of the generalization gradient, and a decreased width of model-derived generalization parameters. Moreover, D2R-blockade modulated similarity-based responses in the hippocampus and decreased midbrain-hippocampal connectivity, which in turn correlated with individual differences in generalization. These results suggest that dopaminergic activity in the hippocampus may relate to the degree of generalization and highlight a potential target for treatment.