A erosão hídrica é a principal causa de degradação do solo em ambientes tropicais e subtropicais úmidos e a perda da camada superficial do solo é o maior desafio para sustentabilidade da agricultura no mundo. Ela afeta a qualidade e o volume dos corpos d'água e diminuí a qualidade dos solos. Apesar disso, o mercado não é capaz de corrigir estes problemas em razão da sua característica de bens públicos (não-exclusividade e não-rivalidade). Assim, o controle da erosão agrícola gera um serviço benéfico para toda a sociedade, mas os seus custos são exclusivamente dos agricultores. Pagamentos por Serviços Ambientais - PSA são mecanismos de compensações em que os beneficiados pelos serviços pagam os seus provedores. PSA são mecanismos promissores para o financiamento da proteção ambiental e podem complementar as atuais regulações. Entretanto, a literatura atual ainda é limitada em termos de quantificação dos serviços gerados, da sua demanda e sua viabilidade econômica. Este estudo analisa a viabilidade econômica de esquemas de PSA para o controle da poluição hídrica advinda da agricultura no Brasil. O objetivo específico do estudo é estimar ofertas de Serviços Ambientais - SA de conservação do solo. As ofertas de SA foram estimadas para áreas de cana-de-açúcar (na Bacia do Rio Corumbataí) e horticultura (na Sub-Bacia Cabeceiras do Tietê) utilizando uma metodologia de dados mínimos. As ofertas foram estimadas para diferentes práticas agrícolas...

This study aims to measure the causal effect of informal caregiving on the health and health care use of women who are caregivers, using instrumental variables. We use data from South Korea, where daughters and daughters-in-law are the prevalent source of caregivers for frail elderly parents and parents-in-law. A key insight of our instrumental variable approach is that having a parent-in-law with functional limitations increases the probability of providing informal care to that parent-in-law, but a parent-in-law’s functional limitation does not directly affect the daughter-in-law’s health. We compare results for the daughter-in-law and daughter samples to check the assumption of the excludability of the instruments for the daughter sample. Our results show that providing informal care has significant adverse effects along multiple dimensions of health for daughter-in-law and daughter caregivers in South Korea.

The generation, diffusion, absorption and application of new technology, knowledge or ideas are crucial drivers of development. This paper surveys the diverse approaches to innovation adopted by East Asian economies, the problems faced and outcomes achieved, as well as possible policy lessons. Knowledge flows from advanced countries remain the primary source of new ideas in developing economies. The authors evaluate the role of three main channels for knowledge flows to East Asia - international trade, acquisition of disembodied knowledge and foreign direct investment. The paper then looks at the exceptionally fast growth in domestic innovation efforts in Korea, Taiwan (China), Singapore and China, drawing on information about R&D as well as original analysis of patent and patent citation data. Citation analysis shows that while East Asian innovations continue to draw heavily on knowledge flows from the US and Japan, citations to the same or to other East Asian economies are quickly rising, indicating the emergence of national and regional knowledge stocks as a foundation for innovation. A last section pulls together findings about policies and institutions to foster innovation...

This paper provides a review of various applications of cooperative game theory (CGT) to issues of natural and environmental resources. With an increase in the level of competition over environmental and natural resources, the incidents of disputes have been at the center of allocation agreements. The paper reviews the cases of common pool resources such as fisheries and forests, and cases of environmental pollution such as acid rain, flow, and stock pollution. In addition to providing examples of cooperative solutions to allocation problems, the conclusion from this review suggests that cooperation over scarce environmental and natural resources is possible under a variety of physical conditions and institutional arrangements. CGT applications to international fishery disputes are especially useful in that they have been making headway in policy-related agreements among states and regions of the world. Forest applications are more local in nature, but of great relevance in solving disputes among communities and various levels of governments.

Background: A tragedy of the commons arises if individuals cannot protect their future use of a depletable resource, and individual fitness increases if individuals exploit the resource at rates beyond sustainability. Natural selection then forces the individuals to diminish, perhaps even to destroy, their resource. One way to protect future use is privatization - that is, locally excluding rivals from the resource. Another is to reduce rivalry among individuals by restricting exploitation rates.

There is considerable debate in economics literature on whether a decision by developing countries to strengthen their protection of intellectual property rights (IPRs) will increase or reduce their access to modern technologies invented by industrial countries. This access can be achieved through technology transfer of various kinds, including foreign direct investment and licensing. Licensing is the focus of this paper.To the extent that inventing firms choose to act more monopolistically and offer fewer technologies on the market, stronger IPRs could reduce international technology flows. However, to the extent that IPRs raise the returns to innovation and licensing, these flows would expand. In theory, the outcome depends on how IPRs affect several variables-the costs of, and returns to, international licensing; the wage advantage of workers in poor countries; the innovation process in industrial countries; and the amount of labor available for innovation and production. The authors develop a theoretical model in which firms in the North (industrial countries) innovate products of higher quality levels and decide whether to produce in the North or transfer production rights to the South (developing countries) through licensing. Different quality levels of each product are sold in equilibrium because of differences in consumers' willingness-to-pay for quality improvements. Contracting problems exist because the inventors in the North must indicate to licensees in the South whether their product is of higher or lower quality and also prevent the licensees from copying the technology. So...

The authors analyze the considerations that lead policymakers to undertake extension investments as a key public responsibility, as well as the complex set of factors and intra-agency incentives that explain why different extension systems' performance vary. The authors provide a conceptual framework outlining farmers' demand for information, the welfare economic characterizations of extension services, and the organizational and political attributes that govern the performance of extension systems. They use the conceptual framework to examine several extension modalities and to analyze their likely and actual effectiveness. Specifically, the modalities reviewed include "training and visit" extension, decentralized systems, "fee-for-service" and privatized extension, and farmer-field-schools. The authors also discuss methodological issues pertaining to the assessment of extension outcomes and review the empirical literature on extension impact. They emphasize the efficiency gains that can come from locally decentralized delivery systems with incentive structures based largely on private provision that in most poorer countries is still publicly-funded. In wealthier countries...

Problem: In the study of conflicts, both economists and evolutionary biologists use the concepts ‘tragedy of the commons’ and ‘public goods dilemma’. What is the relationship between the economist and evolutionist views of these concepts? Model features: The economics literature defines the tragedy of the commons and the public goods dilemma in terms of rivalry and excludability of the good. In contrast, evolutionists define these conflicts based on fitness functions with two components: individual and group components of fitness. Mathematical method: Evolutionary game theory and the calculation of evolutionarily stable strategy trait values by standard optimization techniques and by replacing slopes of group phenotype on individual genotype by coefficients of relatedness. Conclusion: There is a direct relationship between rivalry and the individual component of fitness and between excludability and the group component of fitness. Moreover, although the prisoner’s dilemma constitutes a suitable metaphor to analyse both the public goods dilemma and the tragedy of the commons, it gives the false idea that the two conflicts are symmetric since they refer to situations in which individuals consume a common resource – tragedy of the commons – or contribute to a collective action or common good – public goods dilemma. However...

It is becoming increasingly difficult to reconcile the observed extent of horizontal gene transfers with the central metaphor of a great tree uniting all evolving entities on the planet. In this manuscript we describe the Public Goods Hypothesis and show that it is appropriate in order to describe biological evolution on the planet. According to this hypothesis, nucleotide sequences (genes, promoters, exons, etc.) are simply seen as goods, passed from organism to organism through both vertical and horizontal transfer. Public goods sequences are defined by having the properties of being largely non-excludable (no organism can be effectively prevented from accessing these sequences) and non-rival (while such a sequence is being used by one organism it is also available for use by another organism). The universal nature of genetic systems ensures that such non-excludable sequences exist and non-excludability explains why we see a myriad of genes in different combinations in sequenced genomes. There are three features of the public goods hypothesis. Firstly, segments of DNA are seen as public goods, available for all organisms to integrate into their genomes. Secondly, we expect the evolution of mechanisms for DNA sharing and of defense mechanisms against DNA intrusion in genomes. Thirdly...

Urban open space provides both social and environmental services that range from �private� to �public� goods. This paper investigates the relationship between urban open space public and private goods and human wellbeing, to identify effective planning and management strategies based on theory and case studies of Ottawa and Canberra. The paper constructs a framework for effective management based on the economic principles of excludability, rivalry and devolved governance. This framework is the basis of an analysis of literature and exploration of unpublished surveys and reports on the gazetting and operation of open space networks in Ottawa and Canberra. Historically, gazetting urban open space provides �public� ecosystem services (i.e. Non-excludable and non-rival) however, in operation; these open spaces offer a variety of services ranging from public to private goods. The findings indicate that urban open spaces are most effectively established by government. However in operation, they are more effectively managed collaboratively. By adopting the framework of excludability, rivalry and devolved governance, policy makers can better allocate resources for effective management of urban open space for human wellbeing.

In this paper we, like several studies in the recent literature, employ a Bayesian approach to estimation and inference in models with endogeneity concerns by imposing weaker prior assumptions than complete excludability. When allowing for instrument impe

We thank María Angeles de Frutos, Rajat Deb, Emilio Gutiérrez, Rich McLean, Hervé Moulin, and William Thomson for their comments. We are especially grateful to Shinji Ohseto for his comments and helpful suggestions. We are grateful to an Associate Editor and three referees of this journal for many invaluable comments and suggestions. Jordi Massó acknowledges financial support from the Spanish Ministry of Economy and Competitiveness, through the Severo Ochoa Programme for Centers of Excellence in R&D (SEV-2011-0075) and FEDER grant ECO2008-04756 (Grupo Consilidado-C), and from the Generalitat de Catalunya, through the prize "ICREA Academia" for excellence in research and grant SGR2009-419. Antonio Nicolò’s work is partially supported by the project "Intelligent Preference reasoning for multi-agent decision making" (Univ. of Padua).; We study efficiency and fairness properties of the equal cost sharing with maximal participation (ECSMP) mechanism in the provision of a binary and excludable public good. According to the maximal welfare loss criterion, the ECSMP is optimal within the class of strategyproof, individually rational and no-deficit mechanisms only when there are two agents. In general the ECSMP mechanism is not optimal: we provide a class of mechanisms obtained by symmetric perturbations of ECSMP with strictly lower maximal welfare loss. We show that if one of two possible fairness conditions is additionally imposed...

The paper examines the complex ways in which public goods are regulated. The provision and distribution of public goods is deeply affected by the degree of excludability of those goods and the regulatory context of that excludability. Using a decentered conception of regulation, the paper shows through various examples how state and non-state actors regulate each other's capacities to provide, access, and distribute public goods. The paper includes a discussion of the regulation of knowledge by the rules of intellectual property.

This paper identifies four economic tendencies that shaped the development of the international recorded music industry since 1945: the importance of endogenous sunk costs led to a quality race; the fact that marginal revenue equalled marginal profit led to extreme vertical integration; the quasi-public good character of musicits non-diminishability but partial excludabilityled to a sharply unequal income distribution among stars and the pioneering of new business models to transform consumer into producer surplus; and finally, the project-based character of music production led to decentralised agglomeration. What can be characterised as rights-based multinationals emerged as a response to these forces. They married extreme vertical integration and a portfolio of A&R labels having limited economies of scale and scope, with a global distribution and marketing machine. This paper tries to explain how they emerged and how they can explain increasing industrial concentration in the face of sharp growth of the market and of musical diversity.