910 research outputs found

    Raising capital in an insurance oligopoly market

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    We consider an oligopoly of firms that compete on price. Firms produce a non-stochastic output, insurance coverage, which is sold before the true cost is known. They behave as if they were risk-averse for a standard reason of costly external finance. The model consists in a two-stage game. At stage 1, each firm chooses its internal capital level. At stage 2, firms compete on price. We characterize the conditions for Nash equilibria and analyze the strategic impact of capital choice on the market. We discuss the model with regard to insurance industry specificity and regulation.Price Competition; Risk-averse Firms; Insurance Market; Capital Choice.

    Crinoid phylogeny: a preliminary analysis (Echinodermata: Crinoidea)

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    We describe the first molecular and morphological analysis of extant crinoid high-level inter-relationships. Nuclear and mitochondrial gene sequences and a cladistically coded matrix of 30 morphological characters are presented, and analysed by phylogenetic methods. The molecular data were compiled from concatenated nuclear-encoded 18S rDNA, internal transcribed spacer 1, 5.8S rDNA, and internal transcribed spacer 2, together with part of mitochondrial 16S rDNA, and comprised 3,593 sites, of which 313 were parsimony-informative. The molecular and morphological analyses include data from the bourgueticrinid Bathycrinus; the antedonid comatulids Dorometra and Florometra; the cyrtocrinids Cyathidium, Gymnocrinus, and Holopus; the isocrinids Endoxocrinus, and two species of Metacrinus; as well as from Guillecrinus and Caledonicrinus, whose ordinal relationships are uncertain, together with morphological data from Proisocrinus. Because the molecular data include indel-rich regions, special attention was given to alignment procedure, and it was found that relatively low, gene-specific, gap penalties gave alignments from which congruent phylogenetic information was obtained from both well-aligned, indel-poor and potentially misaligned, indel-rich regions. The different sequence data partitions also gave essentially congruent results. The overall direction of evolution in the gene trees remains uncertain: an asteroid outgroup places the root on the branch adjacent to the slowly evolving isocrinids (consistent with palaeontological order of first appearances), but maximum likelihood analysis with a molecular clock places it elsewhere. Despite lineage-specific rate differences, the clock model was not excluded by a likelihood ratio test. Morphological analyses were unrooted. All analyses identified three clades, two of them generally well-supported. One well-supported clade (BCG) unites Bathycrinus and Guillecrinus with the representative (chimaeric) comatulid in a derived position, suggesting that comatulids originated from a sessile, stalked ancestor. In this connection it is noted that because the comatulid centrodorsal ossicle originates ontogenetically from the column, it is not strictly correct to describe comatulids as unstalked crinoids. A second, uniformly well-supported clade contains members of the Isocrinida, while the third clade contains Gymnocrinus, a well-established member of the Cyrtocrinida, together with the problematic taxon Caledonicrinus, currently classified as a bourgueticrinid. Another cyrtocrinid, Holopus, joins this clade with only weak molecular, but strong morphological support. In one morphological analysis Proisocrinus is weakly attached to the isocrinid clade. Only an unusual, divergent 18S rDNA sequence was obtained from the morphologically strange cyrtocrinid Cyathidium. Although not analysed in detail, features of this sequence suggested that it may be a PCR artefact, so that the apparently basal position of this taxon requires confirmation. If not an artefact, Cyathidium either diverged from the crinoid stem much earlier than has been recognised hitherto (i.e., it may be a Palaeozoic relic), or it has an atypically high rate of molecular evolution

    A dynamic model of extreme risk coverage : resilience and efficiency in the global reinsurance market

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    This paper presents a dynamic model of the reinsurance market for catastrophe risks. The model is based on the classical capacity-constraint assumption. Reinsurers choose every year the quantity of risk they cover and the level of external capital they raise to cover these risks. The model exhibits time dependency and reproduces a market dynamics that shares many features with the real market. In particular, market price increases and reinsurance coverage decreases after large shocks, and a series of smaller losses may have a deeper impact than one larger loss. There is a significant oligopoly effect reducing reinsurance supply, and the market is segregated into strategic large actors that influence market prices and price-taker smaller firms. A regulation trade-off between market efficiency and resilience is identified and quantified: improving the ability of the market to cope with exceptional events increases the cost of reinsurance. This model provides an interesting basis to analyze further capacity needs for the insurance industry in view of growing worldwide exposure to catastrophic risks and climate change.Markets and Market Access,Insurance&Risk Mitigation,Climate Change Economics,Debt Markets,Emerging Markets

    A new genus of deep-sea Majid crab : Griffinia gen. nov. (Crustacea, Decapoda, Brachyura)

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    A new record from north-western Australia permits the description of the first male of #Griffinia lappace (Rathbun, 1918) comb. nov. The morphological features and the shape of the first pleopod merit the creatuib of a new genus for this deep sea species : #Griffinia gen. nov. This new includes two other Pacific species, #G. gilloloensis (Rathbun, 1916) and #G. polita (Griffin and Tranter, 1986). (Résumé d'auteur

    A new species of Sphenocarcinus A. Milne Edwards, 1875 from tasmandis guyots, S. lowryi n. sp. (crustacea : decapoda : brachyura) with notes on the taxonomic status of the genus

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    Une nouvelle espèce de #Sphenocarcinus à rostre bifide, #S. lowryi, est décrite de la mer de Tasman. Cela porte à 17 le nombre des espèces du genre #Sphenocarcinus$. (Résumé d'auteur
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