3,760 research outputs found
The impact of intermediary remuneration in differentiated insurance markets
This article deals with the impact of intermediaries on insurance market transparency and performance. In a market exhibiting product differentiation and coexistence of perfectly and imperfectly informed consumers, competition among insurers leads to non-existence of a pure-strategy market equilibrium. Consumers may become informed about product suitability by consulting an intermediary. We explicitly model two intermediary remuneration systems: commissions and fees. We find that social welfare under fees is first-best efficient but fees lead to lower expected profits of insurers and non-existence of a pure-strategy market equilibrium. Commissions, in contrast, cause 'overinformation' of consumers relative to minimal social cost, but yield a full-information equilibrium in pure strategies associated with higher expected profits of insurers. This might explain why intermediaries are generally compensated by insurers. --product differentiation,intermediation,insurance oligopoly
Towards finite-dimensional gelation
We consider the gelation of particles which are permanently connected by
random crosslinks, drawn from an ensemble of finite-dimensional continuum
percolation. To average over the randomness, we apply the replica trick, and
interpret the replicated and crosslink-averaged model as an effective molecular
fluid. A Mayer-cluster expansion for moments of the local static density
fluctuations is set up. The simplest non-trivial contribution to this series
leads back to mean-field theory. The central quantity of mean-field theory is
the distribution of localization lengths, which we compute for all
connectivities. The highly crosslinked gel is characterized by a one-to-one
correspondence of connectivity and localization length. Taking into account
higher contributions in the Mayer-cluster expansion, systematic corrections to
mean-field can be included. The sol-gel transition shifts to a higher number of
crosslinks per particle, as more compact structures are favored. The critical
behavior of the model remains unchanged as long as finite truncations of the
cluster expansion are considered. To complete the picture, we also discuss
various geometrical properties of the crosslink network, e.g. connectivity
correlations, and relate the studied crosslink ensemble to a wider class of
ensembles, including the Deam-Edwards distribution.Comment: 18 pages, 4 figures, version to be published in EPJ
The optimal pricing strategy for an insurer when risk preferences are stochastically distributed
The present paper analyzes the demand for insurance when the insurer has incomplete information about types of potential customers. We assume that customers´ risk preferences cannot be distinguished by the insurer. Therefore, the standard result in insurance economics that the insurer discriminates perfectly in prices cannot be applied. Instead, the present article examines the optimal pricing rule for an insurer faced with stochastic distribution of risk preferences. Within this general model framework, we show that an optimal strategy always exists. Both fixed and proportionate premium loadings (relative to expected loss) are considered. -- Der vorliegende Artikel analysiert die optimale Prämienpolitik eines Versicherers bei stochastischer Verteilung der Nachfragertypen auf Basis einer Preis-Absatz-Funktion. Dem Versicherer ist hier lediglich die Wahrscheinlichkeitsverteilung der individuellen Nachfragertypen bekannt und eine üblicherweise postulierte vollständige Preisdiskriminierung des Versicherers ist daher nicht möglich. Die allgemeine Preis-Absatz-Funktion des Versicherers variiert in Abhängigkeit der verwendeten Modellparameter. Wir zeigen, dass in diesem allgemeinen Modellrahmen stets eine optimale Preispolitik des Versicherers existiert. Dabei wird in Bezug auf den aktuariell fairen Wert der Police sowohl ein fixer als auch ein proportionaler Prämienzuschlag des Versicherers berücksichtigt.insurance demand,optimal insurance pricing,stochastically distributed risk preferences
Mechanical properties of branched actin filaments
Cells moving on a two dimensional substrate generate motion by polymerizing
actin filament networks inside a flat membrane protrusion. New filaments are
generated by branching off existing ones, giving rise to branched network
structures. We investigate the force-extension relation of branched filaments,
grafted on an elastic structure at one end and pushing with the free ends
against the leading edge cell membrane. Single filaments are modeled as
worm-like chains, whose thermal bending fluctuations are restricted by the
leading edge cell membrane, resulting in an effective force. Branching can
increase the stiffness considerably; however the effect depends on branch point
position and filament orientation, being most pronounced for intermediate tilt
angles and intermediate branch point positions. We describe filament networks
without cross-linkers to focus on the effect of branching. We use randomly
positioned branch points, as generated in the process of treadmilling, and
orientation distributions as measured in lamellipodia. These networks reproduce
both the weak and strong force response of lamellipodia as measured in
force-velocity experiments. We compare properties of branched and unbranched
networks. The ratio of the network average of the force per branched filament
to the average force per unbranched filament depends on the orientation
distribution of the filaments. The ratio exhibits compression dependence and
may go up to about 4.5 in networks with a narrow orientation distribution. With
orientation distributions measured in lamellipodia, it is about two and
essentially independent from network compression, graft elasticity and filament
persistence length
Deployment verification of large CFRP helical high-gain antenna for AIS signals
Deployment verification of large CFRP helical high-gain antenna for AIS signal
Urban Growth in Germany – The Impact of Localization and Urbanization Economies
This study examines the impact of localization and urbanization economies as well as the impact of city size on urban growth in German cities from 2003 to 2007. Although, from a theoretical perspective, agglomeration economies are supposed to have positive impacts on regional growth, prior empirical studies do not show consistent results. Especially little is known about agglomeration economies in Germany, where interregional support policy and the characteristics of the federal system are further determinants of urban growth. The results of the econometric analysis show a U-shaped relationship between specialization and urban growth, which particularly holds for manufacturing industries. We do not find evidence for the impact of Jacobs-externalities; however, city size shows a positive (but decreasing) effect on urban growth.agglomeration, localization economies, urbanization economies, urban growth, specialization, diversification
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