A general lagrangian approach for non-concave moral hazard problems

We establish a general Lagrangian for the moral hazard problem which generalizes the well known first order approach (FOA). It requires that besides the multiplier of the first order condition, there exist multipliers for the second order condition and for the binding actions of the incentive compatibility constraint. Some examples show that our approach can be useful to treat the finite and infinite state space cases. One of the examples is solved by the second order approach. We also compare our Lagrangian with 1\1irrlees'.

A general lagrangian approach for non-concave moral hazard problems

We establish a general Lagrangian for the moral hazard problem which generalizes the well known first order approach (FOA). It requires that besides the multiplier of the first order condition, there exist multipliers for the second order condition and for the binding actions of the incentive compatibility constraint. Some examples show that our approach can be useful to treat the finite and infinite state space cases. One of the examples is solved by the second order approach. We also compare our Lagrangian with 1\1irrlees'.

On the efficiency of equal sacrifice income tax schedules

In an economy which primitives are exactly those in Mirrlees (1971), we investigate the efficiency of labor income tax schedules derived under the equal sacrifice principle. Starting from a given government revenue level, we use Werning’s (2007b) approach to assess whether there is an alternative tax schedule to the one derived under the equal sacrifice principle that raises more revenue while delivering less utility to no one. For our preferred parametrizations of the problem we find that inefficiency only arises at very high levels of income. We also show how the multipliers of the Pareto problem may be extracted from the data and used to find the implicit marginal social weights associated with each level of income.

Estímulos fiscais em um modelo estrutural para o Brasil

A atual crise econômica internacional mostrou que o combate a hiatos do produto utilizando apenas a política monetária pode não ser suficiente. Neste contexto, questões sobre a eficácia de estímulos fiscais temporários como política anticíclica foram levantadas, e adicionalmente quais estímulos fiscais seriam mais benéficos às economias. Este trabalho desenvolveu um modelo estrutural DSGE com características e calibrações para a economia brasileira. O objetivo era realizar um exercício com choques fiscais expansionistas, de modo a analisar seus multiplicadores fiscais. Os resultados sugerem que o impacto de gastos correntes do governo obteve melhor multiplicador fiscal, tanto no curto quanto no longo prazo, porém teve efeitos acumulativos decrescentes. Por outro lado, o choque de diminuição da alíquota dos impostos sobre consumo obteve baixos multiplicadores fiscais a curto prazo, porém com efeitos crescentes a longo prazo, alcançando multiplicadores de longo prazo similares aos dos gastos do governo.

Os efeitos macroeconômicos das transferências sociais: uma abordagem de matriz de contabilidade social

Government transfers to individuals and families play a central role in the Brazilian social protection system, accounting for almost 14 per cent of GDP in 2009. While their fiscal and redistributive impacts have been widely studied, the macroeconomic effects of transfers are harder to ascertain. We constructed a Social Accounting Matrix (SAM) for 2009 and estimated short-term multipliers for seven different government monetary transfers . The SAM is a double-entry square matrix depicting all income flows in the economy. The data were compiled from the 2009 Brazilian National Accounts and the 2008/2009 POF, a household budget survey. Our SAM was disaggregated into 56 sectors, 110 commodities, 200 household groups and seven factors of production (capital plus six types of labor, according to schooling). Finally, we ran a set of regressions to separate household consumption into ‘autonomous’ (or ‘exogenous’) and ‘endogenous’ components. More specifically, we are interested in the effects of an exogenous injection into each of the seven government transfers outlined above. All the other accounts are thus endogenous. The so-called demand ‘leaks’ are income flows from the endogenous to exogenous accounts. Leaks—such as savings, taxes and imports—are crucial to determine the multiplier effect of an exogenous injection, as they allow the system to go back to equilibrium. The model assumes that supply is perfectly elastic to demand shocks. It assumes that the families’ propensity to save and consumption profile are fixed—that is, rising incomes do not provoke changes in behaviour. The multiplier effects of the on GDP corresponds to the growth in GDP resulting from each additional dollar injected into each transfer seven government transfers. If the government increased Bolsa Família expenditures by 1 per cent of GDP, overall economic activity would grow by 1.78 per cent, the highest effect. The Continuous Cash Benefit, comes second. Only three transfers— the private-sector and public servants’ pensions and FGTS withdrawals—had multipliers lower than unity. The multipliers for other relevant macroeconomic aggregates—household and total consumption, disposable income etc. —reveal a similar pattern. Thus, under the stringent assumptions of our model, we cannot reject the hypothesis that government transfers targeting poor households, such as the Bolsa Família, help foster economic expansion. Naturally, it should be stressed that the multipliers relate marginal injections into government transfers to short-term economic performance either real growth, or inflation if there is no idle capacity which is also useful to analyze. In the long term, there is no doubt that what truly matters is the growth of the country’s productive capacity.

Protagonismo juvenil: uma avaliação do programa agente jovem de desenvolvimento humano na cidade de Natal RN (2006/2007).

This paper presents a critical rescue of the term youth, while simultaneously is presented as the lifetime of between 15 and 24 years. Rescue two features in the literature. The first considers youth as a transition period and the second phase work that from a predisposition to rebellion. Discusses the design plural of that term, youth recital to this social and historical aspects of different societies to which it relates and highlights the importance of realizing the diversity of it. Where the object of investigation, the Young Agent Program, the overall objective of the study is to evaluate the effectiveness of the actions of the Young Agent Program for Human Development in Natal-RN. Specifically aims to evaluate the effectiveness of the Young Agent Program: a) as an enhancer of the integration of young people in social spaces of family, school and community, b) as to (re) insertion and the incorporation of issues related to health in adolescence, and c ) regarding the work of young people as multipliers of the actions of the program. With regard to the methodological procedures presents a review of the literature on youth, and the categories of human development, leadership and evaluation of youth policies for the construction of theoretical and analytical approach, using documentary data collection in the Municipal Labor and Social Services - SEMT on the Young Agent Program, and interviews with actors involved in the program. Finally, evaluates the effectiveness of the Young Agent Program from the perspective of participants

Estratégias midiáticas na aprendizagem do tema DST/AIDS: ações em rede para reduzir vulnerabilidades de adolescentes e jovens da comunidade de Mãe Luiza, Natal-RN

Youngsters and teenagers are still a very vulnerable group of DST/AIDS. In order to combat this vulnerability the community intervention project being developed in Mãe Luiza neighborhood in the city of Natal-RN, entitled Strengthening Community Action Network for Prevention in HIV/AIDS: knowledge and Intervene emerged, popularly known as Project Viva Mãe Luiza. The project develops workshops of educomunication whose approach involves the DST/AIDS subject with the following media: video, photography, and theater playbook. This research integrates the activities of the project and has as main objective to investigate how strategies and practices of media communication developed in Project Viva Mãe Luiza through workshops of educomunication, assisted learning for the prevention of DST/AIDS and contributed to the reduction of vulnerability to DST/AIDS among adolescents and young participants of the project residents of Mãe Luiza community. The methodological basis was based on intervention research, with the technique of gathering daily field data, literature and documentary, in-depth interviews and ethnographic observation. The qualitative analysis was based on the monitoring of video workshops, photography, theater and primer, respectively, crossed by transverse to the prevention of DST/AIDS, conducted between June 2012 and December 2013 issues. Interviews with eight multipliers, aiming to understand their perceptions of vulnerability, prevention, multiplication and use of media that were part of the project were conducted. The analyzes show that learning workshops educomunication community health repercussions both in the development of individual skills in communication as changing perceptions about the vulnerabilities to which they are exposed, the awareness about prevention at the individual and differentiated actions multiplication in the community

Um método primal-dual aplicado na resolução do problema de fluxo de potência ótimo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A geometric interpretation for transmission real losses minimization through the optimal power flow and its influence on voltage collapse

This work presents an approach for geometric solution of an optimal power flow (OPF) problem for a two bus system (a slack and a PV busses). Additionally, the geometric relationship between the losses minimization and the increase of the reactive margin and, therefore, the maximum loading point, is shown. The algebraic equations for the calculation of the Lagrange multipliers and for the minimum losses value are obtained. These equations are used to validate the results obtained using an OPF program. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Conservação dos invertebrados em área de proteção ambiental litorânea no nordeste do Brasil: contribuições da educação ambiental para a sustentabilidade

Today's society is in a real collapse of an environmental nature. The populations are lost due to a dream of development without thinking of the consequences that said development can bring to human populations. Thus, it is necessary that strategies be developed for the purpose of protecting the flora and fauna that is at risk from suffering the pressure to achieve this development. Thus important issues involving the need to conserve nature and the creation of protected areas as these strategies are increasingly being developed in research, whether in the biological and / or social. In this sense, the aim of this research through environmental perception social actors for the formation of significant elements for understanding the relationship between man and nature, and from there to provide actions for sensitization. As well as changing attitudes towards environmental issues, to thereby provide analysis based on Environmental Education in order to provide the production of environmental knowledge as a tool that provides value shift. This area of research was to study the Environmental Protection Area Jenipabu - APA Jenipabu, located in northeastern Brazil. Where, from the environmental perception of students from schools within and around this Nature Conservation Unit notes were made regarding the value and meaning given by students, and how this, the feeling of belonging to these groups. This dissertation is composed of two chapters, the first is titled Environmental perception and feeling of belonging in the area of environmental protection in coastal RN - Brazil, where it makes a diagnosis of how these groups understands and realizes the Unity of Nature Conservation. The second, which is titled Construction of environmental knowledge and conservation of invertebrates in the Environmental Protection Area in the northeast coast of Brazil, specifically developed in the school from within the APA Jenipabu, in order to promote a sense of belonging for those students who become multipliers, in order to realize the importance and necessity of having this unit for Nature Conservation. Looking to the degree of importance of environmental education as a tool to raise awareness on conservation of invertebrates and is all the fauna and flora exists, whether in a conservation of nature or not

Interpolating EFGM for computing continuous and discontinuous electromagnetic fields

Purpose - This paper proposes an interpolating approach of the element-free Galerkin method (EFGM) coupled with a modified truncation scheme for solving Poisson's boundary value problems in domains involving material non-homogeneities. The suitability and efficiency of the proposed implementation are evaluated for a given set of test cases of electrostatic field in domains involving different material interfaces.Design/methodology/approach - the authors combined an interpolating approximation with a modified domain truncation scheme, which avoids additional techniques for enforcing the Dirichlet boundary conditions and for dealing with material interfaces usually employed in meshfree formulations.Findings - the local electric potential and field distributions were correctly described as well as the global quantities like the total potency and resistance. Since, the treatment of the material interfaces becomes practically the same for both the finite element method (FEM) and the proposed EFGM, FEM-oriented programs can, thus, be easily extended to provide EFGM approximations.Research limitations/implications - the robustness of the proposed formulation became evident from the error analyses of the local and global variables, including in the case of high-material discontinuity.Practical implications - the proposed approach has shown to be as robust as linear FEM. Thus, it becomes an attractive alternative, also because it avoids the use of additional techniques to deal with boundary/interface conditions commonly employed in meshfree formulations.Originality/value - This paper reintroduces the domain truncation in the EFGM context, but by using a set of interpolating shape functions the authors avoided the use of Lagrange multipliers as well Mathematics in Engineering high-material discontinuity.

Nonlinear Dynamics and Control of an Ideal/Nonideal Load Transportation System With Periodic Coefficients

In this paper, a loads transportation system in platforms or suspended by cables is considered. It is a monorail device and is modeled as an inverted pendulum built on a car driven by a dc motor the governing equations of motion were derived via Lagrange's equations. In the mathematical model we consider the interaction between the dc motor and the dynamical system, that is, we have a so called nonideal periodic problem. The problem is analyzed, qualitatively, through the comparison of the stability diagrams, numerically obtained, for several motor torque constants. Furthermore, we also analyze the problem quantitatively using the Floquet multipliers technique. Finally, we devise a control for the studied nonideal problem. The method that was used for analysis and control of this nonideal periodic system is based on the Chebyshev polynomial exponsion, the Picard iterative method, and the Lyapunov-Floquet transformation (L-F transformation). We call it Sinha's theory.

The application of interpolating MLS approximations to the analysis of MHD flows

The element-free Galerkin method (EFGM) is a very attractive technique for solutions of partial differential equations, since it makes use of nodal point configurations which do not require a mesh. Therefore, it differs from FEM-like approaches by avoiding the need of meshing, a very demanding task for complicated geometry problems. However, the imposition of boundary conditions is not straightforward, since the EFGM is based on moving-least-squares (MLS) approximations which are not necessarily interpolants. This feature requires, for instance, the introduction of modified functionals with additional unknown parameters such as Lagrange multipliers, a serious drawback which leads to poor conditionings of the matrix equations. In this paper, an interpolatory formulation for MLS approximants is presented: it allows the direct introduction of boundary conditions, reducing the processing time and improving the condition numbers. The formulation is applied to the study of two-dimensional magnetohydrodynamic flow problems, and the computed results confirm the accuracy and correctness of the proposed formulation. (C) 2002 Elsevier B.V. All rights reserved.

On a control of a non-ideal mono-rail system with periodics coefficients

In this work, the problem in the loads transport (in platforms or suspended by cables) it is considered. The system in subject is composed for mono-rail system and was modeled through the system: inverted pendulum, car and motor and the movement equations were obtained through the Lagrange equations. In the model, was considered the interaction among of the motor and system dynamics for several potencies motor, that is, the case studied is denominated a non-ideal periodic problem. The non-ideal periodic problem dynamics was analyzed, qualitatively, through the comparison of the stability diagrams, numerically obtained, for several motor torque constants. Furthermore, one was made it analyzes quantitative of the problem through the analysis of the Floquet multipliers. Finally, the non-ideal problem was controlled. The method that was used for analysis and control of non-ideal periodic systems is based on the Chebyshev polynomial expansion, in the Picard iterative method and in the Lyapunov-Floquet transformation (L-F trans formation). This method was presented recently in [3-9].

On non-linear dynamics and a periodic control design applied to the potential of membrane action

The Fitzhugh-Nagumo (fn) mathematical model characterizes the action potential of the membrane. The dynamics of the Fitzhugh-Nagumo model have been extensively studied both with a view to their biological implications and as a test bed for numerical methods, which can be applied to more complex models. This paper deals with the dynamics in the (FH) model. Here, the dynamics are analyzed, qualitatively, through the stability diagrams to the action potential of the membrane. Furthermore, we also analyze quantitatively the problem through the evaluation of Floquet multipliers. Finally, the nonlinear periodic problem is controlled, based on the Chebyshev polynomial expansion, the Picard iterative method and on Lyapunov-Floquet transformation (L-F transformation).