6,828 research outputs found

    Novel Algorithms for LDD Motif Search

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    Background: Motifs are crucial patterns that have numerous applications including the identification of transcription factors and their binding sites, composite regulatory patterns, similarity between families of proteins, etc. Several motif models have been proposed in the literature. The (l,d)-motif model is one of these that has been studied widely. However, this model will sometimes report too many spurious motifs than expected. We interpret a motif as a biologically significant entity that is evolutionarily preserved within some distance. It may be highly improbable that the motif undergoes the same number of changes in each of the species. To address this issue, in this paper, we introduce a new model which is more general than (l,d)-motif model. This model is called (l,d1,d2)-motif model (LDDMS) and is NP-hard as well. We present three elegant as well as efficient algorithms to solve the LDDMS problem, i.e., LDDMS1, LDDMS2 and LDDMS3. They are all exact algorithms. Results: We did both theoretical analyses and empirical tests on these algorithms. Theoretical analyses demonstrate that our algorithms have less computational cost than the pattern driven approach. Empirical results on both simulated datasets and real datasets show that each of the three algorithms has some advantages on some (l,d1,d2) instances. Conclusions: We proposed LDDMS model which is more practically relevant. We also proposed three exact efficient algorithms to solve the problem. Besides, our algorithms can be nicely parallelized. We believe that the idea in this new model can also be extended to other motif search problems such as Edit-distance-based Motif Search (EMS) and Simple Motif Search (SMS)

    When prices hardly matter: Incomplete insurance contracts and markets for repair goods

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    This paper looks at markets characterized by the fact that the demand side is insured. In these markets a consumer purchases a good to compensate consequen¬ces of unfavorable events, such as an accident or an illness. Insurance policies in most lines of insurance base indemnity on the insured’s actual expenses, i.e., the insured would be partially or completely reimbursed when purchasing certain goods. In this setting we discuss the interaction between insurance and repair markets by focusing, on the one hand, upon the development of prices and the structure of markets with insured consumers, and, on the other hand, the resulting backlash on optimal insurance contracting. We show that even in the absence of ex post moral hazard the extension of insurance coverage will lead to an increase in prices as well as to a socially undesirable increase in the number of repair service suppliers, if repair markets are imperfect

    Merging Automobile Insurance Regulatory Bodies: The Case of Atlantic Canada

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    The recent automobile liability insurance crisis in Atlantic Canada has prompted the four provincial legislations (Newfoundland and Labrador, New Brunswick, Nova Scotia and Prince Edward Island) to setup a task force to redesign, if necessary, the personal automobile insurance system. After reviewing some of the most interesting new regulatory changes, our paper proposes a new area of discussion: The merger of the four provincial insurance regulatory bodies to combat insurance fraud. We base our paper on the principle that recent premium increases are mainly due to an increase in insurance fraud. We show that merging the regulatory bodies may reduce insurance fraud if the merger allows savings on the average audit cost and on the development of better fraud detection technology. Finally, we suggest a fraud reducing insurance taxation scheme to finance insurance fraud investigations. La rĂ©cente crise dans le Canada Atlantique au sujet de l'assurance de la responsabilitĂ© civile des automobilistes a contraint les gouvernements des quatre provinces (Terre-Neuve et Labrador, Nouveau-Brunswick, Nouvelle-Écosse et l'Île-du-Prince-Édouard) Ă  mettre en place une commission pour Ă©tudier la possibilitĂ© de rĂ©organiser, si nĂ©cessaire, leur systĂšme d'assurance automobile. AprĂšs avoir analysĂ© les plus intĂ©ressantes modifications Ă  la rĂ©glementation mises en place dans ces provinces, notre Ă©tude offre un nouveau terrain de discussion, soit la fusion des quatre rĂ©glementations provinciales afin de combattre la fraude Ă  l'assurance. Notre Ă©tude se base sur le principe que les rĂ©centes augmentations dans les primes sont attribuables Ă  une augmentation de la fraude Ă  l'assurance dans ces provinces. En fusionnant les rĂ©glementations des quatre provinces, nous montrons que la fraude Ă  l'assurance peut diminuer si la fusion permet d'Ă©pargner une partie du coĂ»t de vĂ©rification encouru par les assureurs lors de rĂ©clamations douteuses. Également, nous montrons qu'une telle fusion peut permettre de dĂ©velopper une meilleure technologie de vĂ©rification des rĂ©clamations. Nous terminons le papier en suggĂ©rant un systĂšme de taxation particulier qui non seulement peut financer les investissements nĂ©cessaires pour combattre la fraude, mais peut Ă©galement rĂ©duire la fraude directement.insurance fraud, asymmetric information, insurance taxation, public policy, fraude Ă  l'assurance, information asymĂ©trique, taxation Ă  l'assurance, politique publique

    Merging automobile regulatory bodies: The case of Atlantic Canada

    Get PDF
    The recent automobile liability insurance crisis in Atlantic Canada has prompted the four provincial legislations (Newfoundland and Labrador, New Brunswick, Nova Scotia and Prince Edward Island) to setup a task force to redesign, if necessary, the personal automobile insurance system. After reviewing some of the most interesting new regulatory changes, our paper proposes a new area of discussion: The merger of the four provincial insurance regulatory bodies to combat insurance fraud. We base our paper on the principle that recent premium increases are mainly due to an increase in insurance fraud. We show that merging the regulatory bodies may reduce insurance fraud if the merger allows savings on the average audit cost and on the development of better fraud detection technology. Finally, we suggest a fraud reducing insurance taxation scheme to finance insurance fraud investigations. --Insurance Fraud,Asymmetric Information,Insurance Taxation,Public Policy

    When prices hardly matter: Incomplete insurance contracts and markets for repair goods

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    This paper locks at markets charaterized by the fact that the demand side is insured. In these markets a consumer purchases a good to compensate consequences of unfavorable events, such as an accident or an illness. Insurance policies in most lines of insurance base indemnity on the insured's actual expenses, i. e., the insured would be partially or completely reimbursed when purchased certain goods. In this setting we discuss the interaction between insurance and repair markets by focusing, on the one hand, upon on development of prices and the market structure in markets with insured customers, and, on the other hand, the resulting backlash on optimal insurance contracting. --insurance,incomplete contracts,repair markets

    When prices hardly matter: Incomplete insurance contracts and markets for repair goods

    Get PDF
    This paper looks at markets characterized by the fact that the demand side is insured. In these markets a consumer purchases a good to compensate consequen¬ces of unfavorable events, such as an accident or an illness. Insurance policies in most lines of insurance base indemnity on the insured’s actual expenses, i.e., the insured would be partially or completely reimbursed when purchasing certain goods. In this setting we discuss the interaction between insurance and repair markets by focusing, on the one hand, upon the development of prices and the structure of markets with insured consumers, and, on the other hand, the resulting backlash on optimal insurance contracting. We show that even in the absence of ex post moral hazard the extension of insurance coverage will lead to an increase in prices as well as to a socially undesirable increase in the number of repair service suppliers, if repair markets are imperfect.insurance; incomplete contracts; repair markets

    When prices hardly matter: Incomplete insurance contracts and markets for repair goods

    Get PDF
    This paper looks at markets characterized by the fact that the demand side is insured. In these markets a consumer purchases a good to compensate consequences of unfavorable events, such as an accident or an illness. Insurance policies in most lines of insurance base indemnity on the insured’s actual expenses, i.e., the insured would be partially or completely reimbursed when purchasing certain goods. In this setting we discuss the interaction between insurance and repair markets by focusing, on the one hand, upon the development of prices and the market structure in markets with insured customers, and, on the other hand, the resulting backlash on optimal insurance contracting.Incomplete Contracts, Insurance, Repair Markets

    Environmental problems and economic development in an endogenous fertility model

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    Population growth is often viewed as a most oppressive global problem with respect to environmental deterioration, but the relationships between population development, economic dynamics and environmental pollution are complex due to various feedback mechanisms. We analyze society’s economic decisions on birth rates, investment into human and physical capital, and polluting emissions within an optimal control model of the coupled demographic-economic-environmental system. We show that a long-run steady state is optimal that is characterized by a stable pollution stock, and by population and economic growth rates depending on the possibilities of emission abatement and technical progress due to human capital accumulation. We derive a condition on the production technologies and opportunity costs of raising children, under which the optimal birth rate is constant even during the transition to a steady state. In particular in an economy where only human capital is needed to produce output, the optimal choice of the birth rate is not affected by the states of the economy or the environment. In such a setting, the optimal birth rate is constant and policy should concentrate on intertemporal adjustment of per-capita emissions.sustainability, endogenous fertility, externalities

    ErklĂ€rungsansĂ€tze fĂŒr vertragswidriges Verhalten von Versicherungsnehmern aus Sicht der ökonomischen Theorie

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    Ziel dieser Arbeit ist es, in die ökonomische Analyse des Versicherungsbetrugs einzufĂŒhren und einige grundlegende Determinanten fĂŒr vertragswidriges Verhalten von Versicherungsnehmern aufzuzeigen. Dazu werden zunĂ€chst die strategischen Entscheidungsprobleme von Versicherungsnehmern und Versicherern eingehend analysiert und optimales Verhalten unter realitĂ€tsnahen Annahmen hergeleitet, sowie Ansatzpunkte fĂŒr die BetrugsbekĂ€mpfung aufgezeigt. Beispielhaft werden dazu die Auswirkungen von Betrugserkennungssystemen oder die konsequente Anzeige entdeckter BetrĂŒger auf die BekĂ€mpfung von Versicherungsbetrug nĂ€her untersucht. Es zeigt sich, dass beide Ansatzpunkte erheblichen Einfluss auf die Kosten des Versicherungsbetrugs haben können. Ein hĂ€ufig geĂ€ußerter Kritikpunkt an solchen Analysen ist, dass ethische Bedenken der Versicherungsnehmer meist unberĂŒcksichtigt bleiben. Die Einbeziehung von ethischen Bedenken fĂŒhrt aber nicht zwangslĂ€ufig zu einer niedrigeren BetrugshĂ€ufigkeit. Abschließend wird der Frage nachgegangen, inwieweit Versicherungsbetrug auf versicherungsspezifische Faktoren zurĂŒckzufĂŒhren ist und wie bzw. in welchem Umfang Versicherer Einfluss auf die ethische Bewertung des Versicherungsbetrugs durch Versicherungsnehmer nehmen können. -- The two main purposes of this paper are an introduction to the economic analysis of insurance fraud and furthermore a derivation of factors that determine fraudulent behavior of policyholders on insurance markets. Consequently, we analyze the strategic decision problems of insurance companies and the policyholders and identify some factors that can help to reduce fraudulent behavior. In this context we evaluate two derived starting points for the combat against insurance fraud: fraud detection systems and a consequent charge policy of detected defrauders. We illustrate that both points can help to reduce the cost of fraud. Furthermore, we enhance our earlier analysis with respect to the empirical fact that some individuals care about fairness or - in the insurance fraud context - the legitimacy of their actions. Surprisingly, in some market situations these concerns of some policyholders do not lead to a lower fraud probability. Finally, we discuss how and to what extent insurance companies can influence such ethical concerns of policyholders. On that score, we distinguish insurance specific and insurance unspecific factors and their impact on the consumers attitudes towards insurance fraud.
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