Optimal financial contracting and debt maturity structure under adverse selection

We analyze a model in which a risk-averse country finances its development project under asymmetric information. Before the project renders its fruits, two types of news will become available, one of which will reduce the asymmetry of information between the country and its investors. We characterize the optimal financial contract both when complete financial contracting is possible and when the country is restricted to using only short-term and long-term debt.

Managerial Delegation in a Mixed Duopoly with a Foreign Competitor

We examine firms' decisions to hire managers in a duopoly where a public firm competes with a foreign private firm. In contrast with the case in which the public firm competes with a domestic private firm -where only the private firm decides to hire a manager- we find that both firms hire managers. This leads to a social welfare higher than the one obtained when neither firm hires a manager.Mixed oligopoly

Strict calculation of the light statistics at the output of a travelling wave optical amplifier

A new method for calculating the probability density function of the photon number propagating through a travelling wave optical amplifier with no restriction on its working regime (linear and nonlinear) is reported. The authors show that the widely used Gaussian approximation of the probability density function does not match the real statistics if the incident optical power is small.Peer ReviewedPostprint (published version

Practical method for modelling the nonlinear behaviour of a travelling wave semiconductor optical amplifier

The authors present a simple model of a travelling wave semiconductor optical amplifier with an appreciable degree of saturation. The model uses a particular way of linearising the total carrier recombination R(N) to find useful expressions for the saturation parameter and/or the carrier lifetime. By combining these expressions and the gain measurements realised, it is possible to establish the dependence between the mentioned parameters and the input optical power.Peer ReviewedPostprint (published version

Signaling Credibility --- Choosing Optimal Debt and International Reserves

This paper evaluates the challenges facing developing countries when there is uncertainty about the policy maker type. We consider a country characterized by volatile output, inelastic demand for fiscal outlays, high tax collection costs, and sovereign risk, where future output depends on the type of policymaker in place today. There are two policymakers -- type T chooses debt and international reserves to smooth tax collection costs; type S has higher discount factor, aiming at obtaining current resources for narrow interest groups, and preferring not to undertake costly reforms that may enhance future output. Financial markets do not know the type of policymaker in place and try to infer its type by looking at its financial choices. We show that various adverse shocks (lower output, higher real interest rate, etc.) can induce a switch from an equilibrium where each policy maker chooses its preferred policy to another where T distorts its policies in order to separate itself from S in the least costly way. This is accomplished by type T reducing both international reserves and external debt. Further decline in output would induce type T to lower debt, and reserves would fall at a higher rate than otherwise expected.

Mentalidades medioambientales : los discursos sobre el medio ambiente de los andaluces residentes en zonas urbanas

La conciencia medioambiental se ha extendido y generalizado socialmente en los últimos años. Sin embargo, este mayor conocimiento y sensibilización hacia los problemas del medio ambiente no se ha traducido en una extensión similar de los comportamientos medioambientalmente responsables. Esta discordancia entre conciencia y comportamiento medioambiental, puesta de manifiesto en distintas investigaciones, resulta desconcertante, pero puede ser explicada desde las mentalidades medioambientales, entendidas como concepciones del medio ambiente producidas y distribuidas socialmente. En este artículo, se presentan los resultados de una reciente investigación en la que se exploraron las mentalidades medioambientales de los andaluces residentes en zonas urbanas, mediante el análisis de los discursos producidos en grupos de discusión.Environmental concerns have been spread and generalised in the last few years. Nevertheless, this larger knowledge and awareness about environmental issues have not produced a similar expansion of a sense of responsibility in personal behaviours. This gap between environmental concerns and ecological behaviours has puzzled researchers. However, this can be explained by the nature of environmental mentalities, conceptions about the environment which are socially produced and spread. This paper presents the outcomes of a recent research that has explored the environmental mentalities of Andalusian people who live in urban areas. To this end, we have analysed the social discourses produced in a series of focus-groups

Separability conditions from the Landau-Pollak uncertainty relation

We obtain a collection of necessary (sufficient) conditions for a bipartite system of qubits to be separable (entangled), which are based on the Landau-Pollak formulation of the uncertainty principle. These conditions are tested, and compared with previously stated criteria, by applying them to states whose separability limits are already known. Our results are also extended to multipartite and higher-dimensional systems.Comment: 20 page