The Pareto-Frontier in a simple Mirrleesian model of income taxation

We characterize the Pareto-frontier in a simple Mirrleesian model of income taxation. We show how the second-best frontier which incorporates incentive constraints due to private information on productive abilities relates to the first-best frontier which takes only resource constraints into account. In particular, we argue that the second-best frontier can be interpreted as a Laer-curve. We also use this second-best frontier for a comparative statics analysis of how optimal income tax rates vary with the degree of inequity aversion, and for a characterization of optimal public-good provision. We show that a more inequity averse policy maker chooses tax schedules that are more redistributive and involve higher marginal tax rates, but chooses a lower public-goods provision level.Optimal Income Taxation, Public-good provision, Laer-Curve

Mapping RT-LOTOS specifications into Time Petri Nets

RT-LOTOS is a timed process algebra which enables compact and abstract specification of real-time systems. This paper proposes and illustrates a structural translation of RT-LOTOS terms into behaviorally equivalent (timed bisimilar) finite Time Petri nets. It is therefore possible to apply Time Petri nets verification techniques to the profit of RT-LOTOS. Our approach has been implemented in RTL2TPN, a prototype tool which takes as input an RT-LOTOS specification and outputs a TPN. The latter is verified using TINA, a TPN analyzer developed by LAAS-CNRS. The toolkit made of RTL2TPN and TINA has been positively benchmarked against previously developed RT-LOTOS verification tool

The Dynamics of Industry Investments

We study the development of a duopoly in a continuous-time model of capacity investment under no commitment by firms regarding future actions. While capacity units are costly, indivisible, durable, and large relative to market size, early entry cannot secure a first-mover advantage and both firms are active beyond some level of market development. We evaluate the investment real options in that context. In the early industry development phase, the sole Markov Perfect Equilibrium (MPE) is a preemption equilibrium with the first industry investment occurring earlier (hence being riskier) than socially optimal. Once both firms hold capacity, tacit collusion, taking the form of postponed capacity investment, may occur as a MPE. Volatility and the expected speed of market development play a crucial role in competitive behavior: we show that the emergence of tacit collusion equilibria is favored by higher demand volatility, faster market growth, as well as by lower discount rate. Nous étudions le développement d'un duopole dans un modèle en temps continu d'investissement en capacité sans engagement des firmes quant à leurs actions futures. Bien que les unités de capacité soient coûteuses, indivisibles, durables et de taille non négligeable par rapport au marché, l'entrée hâtive ne peut conférer d'avantage durable et à partir d'un certain niveau de développement du marché, les deux firmes sont en activité. Nous évaluons les options réelles d'investissement dans ce contexte. Initialement, le seul équilibre Markovien parfait (ÉMP) est un équilibre de préemption dans lequel le premier investissement en capacité se produit plus tôt et comporte un risque plus élevé que socialement désirable. Une collusion tacite pour retarder les augmentations de capacité subséquentes peut devenir possible en ÉMP. La volatilité du marché et sa vitesse de croissance jouent un rôle crucial : l'émergence d'équilibres de collusion tacite est favorisée par une volatilité plus grande, une croissance plus rapide et un taux d'intérêt ou d'actualisation plus faible.real options, duopoly, preemption, collusion, lumpy investment, options réelles, duopole, préemption, collusion, investissement en bloc

A Dynamic Duopoly Investment Game under Uncertain Market Growth

We model investments in capacity in a homogeneous product duopoly facing uncertain demand growth. Capacity building is achieved through adding production units that are durable and lumpy and whose cost is irreversible. There is no exogenous order of moves, no first-mover or second-mover advantage, no commitment, and no finite horizon; while building their capacity over time, firms compete `a la Cournot in the product market. We investigate Markov Perfect Equilibrium (MPE) paths of the investment game, which may include preemption episodes and tacit collusion episodes. However, when firms have not yet invested in capacity, the sole pattern that is MPEcompatible is a preemption episode with firms investing at different times, but both have equal value. The first such investment may occur earlier, and therefore be riskier, than socially optimal. When both firms hold capacity, tacit collusion episodes may be MPE-compatible with firms investing simultaneously at a postponed time (generating an investment wave in the industry). We show that the emergence of such episodes is favored by higher demand volatility, faster market growth, and lower discount rate (cost of capital).

Political Competition and Mirrleesian Income Taxation: A First Pass

We study Downsian competition in a Mirrleesian model of income taxation. The competing politicians may differ in competence. If politicians engage in vote-share maximization, the less competent politician’s policy proposals are attractive to the minority of rich agents, whereas those of the competent politician are attractive to the majority of poor agents. The less competent politician wins with positive probability, which gives rise to a political failure in the sense of Besley and Coate (1998). Political failures are avoided if politicians maximize winning probabilities. Nevertheless, the two equilibria cannot be Pareto-ranked, the minority may be better off under vote-share maximization.electoral competition, non-linear income taxation, candidate quality

Inflation as a Strategic Response

In this paper, we examine the effect of increases in health care costs and general inflation on optimal insurance policies and waste in a model of imperfect information with costly auditing. We show that in such a setting, individuals will buy more than full insurance. Moreover, as the cost of medical increases, consumers (i.e., patients) reduce their probability of filing injustified claims, at the same time as insurance providers audit with lower probability. As a result, waste associated with costly auditing is reduced. We also show that a general increase in the opportunity cost of illness (reflected through lost wages due to illness) also decreases the likelihood of false claims, of auditing and thus of waste, but not as much as health care costs increase. Nous étudions dans ce document de recherche l'impact d'une augmentation des coûts des soins de santé et de l'inflation en général sur le contrat optimal d'assurance médicale et sur le gaspillage dans une économie où les agents-consommateurs possèdent une information privilégiée et où le principal-assureur doit encourir des coûts d'audit pour vérifier l'information des agents. Nous montrons dans cet article que les agents seront plus que pleinement assurés au sens où l'indemnité reçue est plus grande que la perte encourue. De plus, au fur et à mesure que le coût des soins de santé augmente, les agents réduisent leur probabilité de demander des soins de santé injustifiés, alors que le principal réduit sa probabilité d'audit. En conséquence, le gaspillage associé aux audits onéreux diminue. Nous montrons finalement qu'une augmentation dans le coût de la vie en général (que nous approximons par une augmentation des pertes de salaire encourues à cause de la maladie) réduit également le gaspillage associé aux audits,0501s dans une mesure moindre qu'une augmentation du coût des soins de santé.Health care fraud, asymmetric information, contract theory, Fraude médicale, information asymétrique, théorie des contrats

Elaboration of integrated microelectrodes for the detection of antioxidant species

(Pt–Pt–Ag/AgCl) and (Au–Pt–Ag/AgCl) electrochemical microcells (ElecCell) were developed for the detection of redox species by cyclic voltammetry. A special emphasis was placed on the SU-8 waferlevel passivation process in order to optimize the electrochemical properties of the different “thin film” metallic layers, i.e. gold or platinum for the working electrode, platinum for the counter electrode and silver/silver chloride for the reference electrode. (Au–Pt–Ag/AgCl) microcells were applied for the detection of antioxidant species such as ascorbic and uric acids in phosphate buffer solution, evidencing high sensitivity but low selectivity. Works were extended to skin analysis, demonstrating that a good electrical contact with the skin hydrolipidic film allowed the effective evaluation of the skin global antioxidant capacity