3,482 research outputs found

    Asymptotic Distributions of the Overshoot and Undershoots for the L\'evy Insurance Risk Process in the Cram\'er and Convolution Equivalent Cases

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    Recent models of the insurance risk process use a L\'evy process to generalise the traditional Cram\'er-Lundberg compound Poisson model. This paper is concerned with the behaviour of the distributions of the overshoot and undershoots of a high level, for a L\'{e}vy process which drifts to −∞-\infty and satisfies a Cram\'er or a convolution equivalent condition. We derive these asymptotics under minimal conditions in the Cram\'er case, and compare them with known results for the convolution equivalent case, drawing attention to the striking and unexpected fact that they become identical when certain parameters tend to equality. Thus, at least regarding these quantities, the "medium-heavy" tailed convolution equivalent model segues into the "light-tailed" Cram\'er model in a natural way. This suggests a usefully expanded flexibility for modelling the insurance risk process. We illustrate this relationship by comparing the asymptotic distributions obtained for the overshoot and undershoots, assuming the L\'evy process belongs to the "GTSC" class

    Analyzing a Flat Income Tax in the Netherlands

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    A flat tax rate on income has gained popularity in European countries. This paper assesses the attractiveness of such a flat tax in achieving redistributive objectives with the least cost to labour market performance. We do so by using a detailed applied general equilibrium model for the Netherlands. The model is empirically grounded in the data and encompasses decisions on hours worked, labour force participation, skill formation, wage bargaining between unions and firms, matching frictions, and a wide variety of institutional details. The simulations suggest that the replacement of the current tax system in the Netherlands by a flat rate will harm labour market performance if aggregate income inequality is contained. This finding bolsters the notion that a linear tax is less efficient than a non-linear tax to obtain redistributive goals.flat tax, labour market, general equilibrium, equity, optimal taxation

    Pharmacokinetics, in-vitro activity, therapeutic efficacy and clinical safety of aztreonam vs. cefotaxime in the treatment of complicated urinary tract infections

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    The minimal inhibitory concentrations (MICs) of aztreonam and cefotaxime were determined against 400 isolates from urological in-patients with complicated and/or hospital acquired urinary tract infections (UTI). Against the Gram-negative rods the activities of both antibiotics were comparable except for higher activity of aztreonam against Pseudomonas aeruginosa. The pharmacokinetic study in nine elderly patients showed a prolonged plasma half life of aztreonam (2.7 h) as compared to younger volunteers (1.6-1.9 h). In a prospective randomized study 39 urological patients with complicated and/or hospital acquired UTI were treated with 1 g aztreonam or cefotaxime iv twice daily for 4 to 15 days. Cure was obtained in 5 out of 18 patients in the aztreonam and 7 out of 20 patients in the cefotaxime group. There were 3 superinfections, 7 relapses and 3 reinfections in the aztreonam group and 1 failure, 1 superinfection, 6 relapses and 5 reinfections in the cefotaxime group. There was no significant difference in therapeutic efficacy between the two antibiotics. Both antibiotics were tolerated well and seem to be equally effective in the treatment of complicated UTI caused by sensitive organisms

    CROSS COMPLIANCE AND COMPETITIVENESS OF THE EUROPEAN BEEF AND PIG SECTOR

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    Beef and pig production are important sectors affected by the cross-compliance policy. Full compliance with SMRs and GAECs generates costs and benefits which may have an impact on the competitiveness of these sectors on the world market. Compliance with the Nitrate Directive, animal identification and registration requirements and animal welfare standards can give rise to non-negligible cost of production increases at individual farm level and at sector level. Additional costs can be relevant either due to a low degree of compliance or by significant adjustments costs at farm level. Full compliance generates a level playing field between Member States of the EU, as some countries have to face higher additional costs than others, which are be attributed to differences in degree of compliance. This paper first presents evidence of additional costs at individual farm level due to full compliance. Then for beef and pork a methodology has been developed in order to calculate sector cost impacts following an upcsaling procedure for each of the analysed directives. Simulations with the GTAP model have enabled an assessment of the trade effect of compliance with standards and the impact on the external competitiveness of the EU beef and pork production. In some policy fields covered by cross-compliance important trade partners such as Canada, USA and New Zealand have implemented policies similar to the EU. In these three countries comparable standards to those in the EU were identified and the level and cost of compliance have been assessed. The pig sector will be affected most by a unilateral compliance with standards in the EU, in particular as the Nitrate Directive is concerned. Within the EU pig production costs will rise by 0.545 %. Imports may increase by 4% and exports may fall by 3%. However full application of the Clean Water Act in the US, which contains similar obligations to the Nitrate Directive, generates a significant sector cost increase (1,08%) which may counterbalance the loss of competitiveness of EU pork production towards the US. Compliance with the mandatory animal welfare standards has only minor cost implications and has negligible effects on external competitiveness of the EU both because of a high degree of compliance and relatively low adjustment costs at farm level. Finally, in many EU member states the degree of compliance of beef farms with the animal registration and identification directives is below 100%. Additional costs for full compliance within the EU have been estimated at 0.455%, which may cause an increase of beef imports of 2.21% and a decline of exports of –2.12%. This loss in competitiveness of the EU will further favour the position of Brazil on the world beef market. At the other hand significant benefits are obtained in food security of EU beef.Cross compliance, beef sector, pork sector, Agricultural and Food Policy, Q10, Q18,

    Solvation dynamics in liquids and glasses

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    Glas maken is Ă©Ă©n van die technologieĂ«n waar de mensheid al lang gebruikt van maakt. Al zo’n vijf duizend jaar om precies te zijn. Dus je zou denken dat we inmiddels wel bijna alles weten wat er over glazen te weten valt. Nou, dat valt tegen. Zeker wanneer je de kennis die we hebben van de fysica van kristallen vergelijkt met die van glazen. Het verschil tussen glazen en kristallen is dat de moleculen waaruit deze substanties zijn opgebouwd, in een glas niet netjes geordend in een rooster zitten zoals in een kristal. Het gebrek aan orde in zo’n glas is Ă©Ă©n van de redenen dat fysici niet zoveel met glazen aankunnen. Omdat kristallen een grote interne symmetrie hebben, helpt dit bij het begrijpen van wat er op atomair en moleculair niveau allemaal gebeurt. En van daaruit kun je dan allerlei dagelijkse eigenschappen van kristallen verklaren, zoals de vorm, kleur, warmtegeleiding, hardheid, enzovoort. In mijn onderzoek heb ik me geconcentreerd op twee modellen die toegepast worden om the fysica van glazen (en vloeistoffen) te beschrijven in twee extreme omstandigheden. Die modellen heb ik getest op hun effectiviteit en de toepasbaarheid buiten het nauwe temperatuur gebied waar ze doorgaans worden gebruikt in mijn vakgebied van de niet lineaire optica. Het ene uiterste is de extreem lage temperatuur dicht bij het absolute nulpunt. Toe nu toe waren er extra parameters, matsfactoren, nodig om met het model dat bij deze temperatuur gebruikt wordt accurate voorspellingen te doen. Mijn stelling is dat je die parameters helemaal niet nodig hebt. Als je de wiskunde netter doet en ongewenste experimentele effecten uitsluit dan kun je ook zonder die parameters je onderzoeksdata prima verklaren. Het andere uiterste, de hoge temperatuur waar het glas vloeistof is geworden. Het model dat hier wordt toegepast behandelt bezit een groot aantal intern aanpasbare parameters. Het zou mooi zijn als het niet nodig is deze parameters te veranderen als de je naar andere, lagere, temperaturen gaat. Helaas, bij lagere temperaturen moet het karakter van het model aanzienlijk veranderd worden om aan te blijven sluiten bij de realiteit. Ik laat zien hoe die veranderingen bijna allemaal gerelateerd kunnen worden aan de veranderingen in de dynamica van de vloeistof die in een glas verandert. Dus met een paar aanpassingen, die min of meer voortvloeien uit bestaande glasvormingstheorie, kun je de experimenten toch prima beschrijven

    On American options under the Variance Gamma process

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