Mixed oligopoly, vertical product differentiation and fixed quality-dependent costs

A private and a public firm face fixed quality-dependent costs of production and compete first in quality and then either in prices or in quantities. In the long run the public firm targets welfare maximization whereas the private firm maximizes profits. In the short run both firms compete in prices or quantities to maximize profits. Mixed competition is always socially desirable compared to a private duopoly regardless of the type of competition in the short run and the equilibrium quality ranking. In addition, mixed competition seems to be a more efficient regulatory instrument than the adoption of a minimum quality standard.vertical product differentiation, mixed oligopoly, quality, price and quantity competition

International Strategic Choice of Minimum Quality Standards and Welfare

We study the influence of minimum quality standards in a two-region partial-equilibrium model of vertical product differentiation and trade. Three alternative standard setting arrangements are considered: Full Harmonization, National Treatment and Mutual Recognition. The analysis integrates the choice of a particular standard setting alternative by governments into the model. We provide a set of sufficient conditions for which Mutual Recognition emerges as one regulatory alternative that always improves welfare in both regions when compared to the case without regulation. We show that Mutual Recognition, being the default procedure if governments do not reach a unanimous decision, is the only possible equilibrium of the game.product differentiation, oligopoly, trade, quality standards, policy coordination

The Effects of Abrupt and Graduated Temporal Reductions on Academic Behavior

The author investigated the effects of abrupt and graduated temporal reductions on academic performance. Six elementary school children who were referred to a remedial special education classroom received token reinforcement contingent on the number of correct math problems answered during daily sessions. A multiple baseline across subjects design with replication of baseline and experimental conditions was employed. The design also balanced the order of exposure to an abrupt reduction in time limits (20 - 5 - 20 min.) and a graduated sequence of time reductions (20 - 15 - 10 - 5 - 20 min.). Children also performed copying tasks daily under a constant time limit in order to assess the degree to which the effects of temporal manipulations on one academic behavior (math) generalized to another academic behavior (copying). The findings demonstrated that as a result of systematic temporal reductions students completed more math problems correctly in five minutes than twenty minutes of baseline. More specifically, the findings demonstrated that graduated temporal reductions markedly enhanced the math performance of slow learners. Furthermore, when students were exposed to an abrupt temporal reduction first their math performance declined, whereas, abrupt temporal reductions which followed graduated temporal reductions markedly enhanced both rate and number of correct math problems. A return to baseline conditions demonstrated that the improved math rates were not completely reversible. Additionally, improved math performances were found to be enduring as indicated by two follow-up math probes conducted two and five weeks after the study. Although copying performance improved over the duration of the study, these improvements did not closely correspond with the math time manipulations. Therefore, the effects of temporal manipulations on math performance did not appear to generalize to a non-reinforced behavior (copying words) that was performed under constant time limits

A behavioral model of evolutionary dynamics and optimal regulation of tax evasion

The paper studies the dynamics of compliance in a population of agents that decide whether to engage in tax evasion depending on an evolutionary adaptation process, when payoffs are assumed to have the realistic features of Prospect Theory utilities. The paper also considers the optimal control problem of a tax authority that targets the maximization of the expected stream of tax revenues choosing auditing effort. The analysis produces novel and rich results, including conditions for the convergence to an asymptotically stable interior equilibrium, the existence of multiple equilibria and discontinuities in the optimal control.Web of Science50897

A importância social do teatro trágico euripidiano

O presente trabalho tem como objetivo observar os costumes gregos ou o ethos grego no contexto democrático ateniense das tragédias, em oposição ao pensamento de Eurípides, particularmente na peça Hécuba. Sendo assim, leva em consideração como os heróis homéricos ainda serviam de paradigma para os jovens, inspirando a participação na guerra, e, quem sabe, a própria morte. Assim sendo, propõe questões acerca da guerra, do feminino e da importância social do teatro na vida cotidiana dos helenos, buscando situar a perspectiva euripidiana na sociedade ateniense. Além disso, tenta compreender a distinção entre as peças de Eurípides, no que diz respeito à execução e à crítica, em comparação com as obras de Ésquilo e Sófocle

Social norms and evolutionary tax compliance

The paper studies tax evasion in an evolutionary setting. In addition to standard variables such as the fine individuals may have to pay if found guilty or the probability of being audited, agents' inclination to engage in tax evasion may also be affected by social interactions. Moreover, expected payoffs may include reputational costs or rewards awarded by society after an individual is audited. The paper shows how (i) social norms may play a very important role in defining the long-run evolution of tax evasion and, consequently, that (ii) policymakers should consider reforms that would increase social awareness and information rather than more (financially and politically) expensive traditional auditing instruments; in addition, (iii) fiscal/auditing policies should be carefully tailored to the particular economic and social setting in place in a country.Web of Science89440538

A Topical Formulation of Melatoninergic Compounds Exerts Strong Hypotensive and Neuroprotective Effects in a Rat Model of Hypertensive Glaucoma

Melatonin is of great importance for regulating several eye processes, including pressure homeostasis. Melatonin in combination with agomelatine has been recently reported to reduce intraocular pressure (IOP) with higher efficacy than each compound alone. Here, we used the methylcellulose (MCE) rat model of hypertensive glaucoma, an optic neuropathy characterized by the apoptotic death of retinal ganglion cells (RGCs), to evaluate the hypotensive and neuroprotective efficacy of an eye drop nanomicellar formulation containing melatonin/agomelatine. Eye tissue distribution of melatonin/agomelatine in healthy rats was evaluated by HPLC/MS/MS. In the MCE model, we assessed by tonometry the hypotensive efficacy of melatonin/agomelatine. Neuroprotection was revealed by electroretinography; by levels of inflammatory and apoptotic markers; and by RGC density. The effects of melatonin/agomelatine were compared with those of timolol (a beta blocker with prevalent hypotensive activity) or brimonidine (an alpha 2 adrenergic agonist with potential neuroprotective efficacy), two drugs commonly used to treat glaucoma. Both melatonin and agomelatine penetrate the posterior segment of the eye. In the MCE model, IOP elevation was drastically reduced by melatonin/agomelatine with higher efficacy than that of timolol or brimonidine. Concomitantly, gliosis-related inflammation and the Bax-associated apoptosis were partially prevented, thus leading to RGC survival and recovered retinal dysfunction. We suggest that topical melatoninergic compounds might be beneficial for ocular health

Hypotensive Effect of Nanomicellar Formulation of Melatonin and Agomelatine in a Rat Model: Significance for Glaucoma Therapy

Background: Melatoninergic agents are known to reduce intraocular pressure (IOP). The present study was performed to evaluate the effect of nanomicellar formulations of melatoninergic agents on IOP in the rat. Methods: Tonometry was used to measure IOP in eyes instilled with melatonin or agomelatine. Ocular hypertension was induced by the injection of methylcellulose in the anterior chamber. Results: Melatonin formulated in nanomicelles had a longer lasting hypotonizing effect on IOP with respect to melatonin in saline. Nanomicellar formulations of melatonin and agomelatine, either alone or in combination, had lowering effects that did not depend on their concentration or their combination, which, however, resulted in an increased duration of the hypotonizing effect. The duration of the lowering effect was further increased by the addition of lipoic acid. Conclusions: We demonstrated the effective hypotonizing activity of melatonin and agomelatine in combination with lipoic acid. Although results in animals cannot be directly translated to humans, the possibility of developing novel therapeutical approaches for patients suffering from hypertensive glaucoma should be considered

Study of the effects of salt crystallisation on degradation of limestone rocks

Salt crystallization is widely recognized as a cause of deterioration of porous building materials. In particular, the crystallization pressure of salt crystals growing in confined pores is found to be the main cause for damage. The aim of this study is to better understand the degradation of porous rocks induced by salt crystallisation and correlate such processes with the intrinsic characteristics of materials. With this intend, an experimental salt weathering simulation has been carried out on two limestones widely used in the Baroque architecture of eastern Sicily. A systematic approach including petrographic, porosimetric and colorimetric analyses, was used to evaluate the correlation among salt crystallisation, microstructural and chromatic variations of limestone. Results showed a quite different resistance of the two limestones to salt damage, and this was found to be strongly dependent on their pore structure and textural characteristics