Review of river fisheries valuation in West and Central Africa

This paper provides a review of the valuation of river fisheries in West and Central Africa. It is the general perception that, compared to the biological and ecological aspects of river fisheries, this particular subject area has received relatively little attention. Economic valuation is concerned with finding expression for what is important in life for human society. It should, therefore, be a central and integral part of government decision-making and policy. The review started with concepts and methods for valuation. Three main types of valuation techniques were identified: conventional economic valuations, economic impact assessments and socioeconomic investigations, and livelihood analysis. On the basis of a literature review, valuation information was then synthesized for the major regional river basins and large lakes, and also used to develop a series of national fisheries profiles. To supplement this broad perspective, a series of case studies are also presented, which focus in particular on the impact of changes in water management regime. Finally, the paper presents an assessment of the three main types of valuation methodology and a set of conclusions and recommendations for future valuation studies

Australasian environmental economics: contributions, conflicts and ‘cop-outs’

Australian and New Zealand environmental economists have played a significant role in the development of concepts and their application across three fields within their subdiscipline: non-market valuation, institutional economics and bioeconomic modelling. These contributions have been spurred on by debates within and outside the discipline. Much of the controversy has centred on the validity of valuations generated through the application of stated preference methods such as contingent valuation. Suggestions to overcome some shortcomings in the work of environmental economists include the commissioning of a sequence of non-market valuation studies to fill existing gaps to improve the potential for benefit transfer.bioeconomic modelling, institutional economics, non-market valuation, Environmental Economics and Policy,

Environmental value and valuation over time

Time and value are related concepts that influence human behaviour. Although classical topics in human thinking throughout the ages, few environmental economic non-market valuation studies have attempted to link the two concepts. Economists have estimated non-market environmental values in monetary terms for over 30 years. This history of valuation provides an opportunity to compare value estimates and how valuation techniques have changed over time. This research aims to compare value estimates of benefits of a protected natural area. In 1978, Nadgee Nature Reserve on the far south coast of New South Wales was the focus of the first application of the contingent valuation method in Australia. This research aims to replicate that study using both the original 1978 contingent valuation method questionnaire and sampling technique, as well as state of the art non-market valuation tools. This replication will provide insights into the extent and direction of changes in environmental values over time. It will also highlight the impact on value estimates of methodological evolution. These insights will help make allocating resources more efficient.Environmental values, temporal variability, non-market valuation, contingent valuation method, choice experiments, incentive compatibility, natural resource management., Environmental Economics and Policy, Land Economics/Use,

Basic Concepts and Common Valuation Errors in Cost-Benefit Analysis

The society has limited resources to meet several objectives such as economic growth, poverty alleviation and environmental protection. These objectives compete for resources and may conflict with each other. For example, economic growth may increase environmental degradation and environmental regulation may constrain growth. Therefore, every effort must be made to reconcile and synergize these diverse social objectives and to prioritize them as to allocate the limited resources among them in the most efficient way. Environmental economics provides us with the analytical tools to reconcile environmental protection with economic growth and other social objectives, and to protect and improve the environment without wasting scarce resources.Cost-benefit analysis

Krull-tropical hypersurfaces

The concepts of tropical-semiring and tropical hypersurface, are extended for an arbitrary ordered group. Then, we define the tropicalization of a polynomial with coefficients in a Krull-valued field. After a close study of the properties of the operator "tropicalization" we conclude with an extension of Kapranov's theorem to algebraically closed fields together with a valuation over an ordered group.Comment: 12 page

Valuation Compressions in VCG-Based Combinatorial Auctions

The focus of classic mechanism design has been on truthful direct-revelation mechanisms. In the context of combinatorial auctions the truthful direct-revelation mechanism that maximizes social welfare is the VCG mechanism. For many valuation spaces computing the allocation and payments of the VCG mechanism, however, is a computationally hard problem. We thus study the performance of the VCG mechanism when bidders are forced to choose bids from a subspace of the valuation space for which the VCG outcome can be computed efficiently. We prove improved upper bounds on the welfare loss for restrictions to additive bids and upper and lower bounds for restrictions to non-additive bids. These bounds show that the welfare loss increases in expressiveness. All our bounds apply to equilibrium concepts that can be computed in polynomial time as well as to learning outcomes

Formal Methods in Conformance Testing: A Probabilistic Refinement

This paper refines the framework of ‘Formal Methods in Conformance Testing’ by introducing probabilities for concepts which have a stochastic nature. Test execution is refined into test runs, where each test run is considered as a stochastic process that returns a possible observa- tion with a certain probability. This implies that not every possible observation that could be made, will actually be made. The development process of an implementation from a specifica- tion is also viewed as a stochastic process that may result in a specific implementation with a certain probability. Together with a weight assignment on implementations this introduces a valuation measure on implementations. The test run probabilities and the valuation measures are integrated in generalized definitions of soundness and exhaustiveness, which can be used to compare test suites with respect to their ability to accept correct, and to reject erroneous implementations

Life Cycle Costing and Food Systems: Concepts, Trends, and Challenges of Impact Valuation

Our global food systems create pervasive environmental, social, and health impacts. Impact valuation is an emerging concept that aims to quantify all environmental, social, and health costs of food systems in an attempt to make the true cost of food more transparent. It also is designed to facilitate the transformation of global food systems. The concept of impact valuation is emerging at the same time as, and partly as a response to, calls for the development of legal mechanisms to address environmental, social, and health concerns. Information has long been understood both as a necessary precursor for regulation and as a regulatory tool in and of itself. With global supply chains and widespread impacts, data necessary to produce robust and complete impact valuation requires participation and cooperation from a variety of food system actors. New costing methods, beyond basic accounting, are necessary to incorporate the scope of impacts and stakeholders. Furthermore, there are a range of unanswered questions surrounding realizations of impact valuation methods, e.g. data sharing, international privacy, corporate transparency, limitations on valuation itself, and data collection standardization. Because of the proliferation of calls for costing tools, this article steps back and assesses the current development of impact valuation methods. In this article, we review current methods and initiatives for the implementation of food system impact valuation. We conclude that in some instances, calls for the implementation of costing have outpaced available and reliable data collection and current costing techniques. Many existing initiatives are being developed without adequate consideration of the legal challenges that hinder implementation. Finally, we conclude with a reminder that although impact valuation tools are most often sought and implemented in service of market-based tools for reform, they can also serve as a basis for robust public policies

WILLINGNESS TO PAY FOR AN INCREASE IN THE QUALITY OF DRINKING WATER: AN APPLICATION TO FRANCE

In this paper a method to infer the value for consumers of the quality of supplied water is presented and applied. It uses concepts developed in the literature of environmental good valuation and the literature of equivalence scale measurement. It is applied to French data.willingness to pay, drinking water, indirect observed method, Environmental Economics and Policy,

On Real Options and Information Costs.

This paper presents a simple framework for the use of traditional capital budgeting models and the valuation of several real options in the presence of shadow costs of incomplete information. Information costs can be viewed as sunk costs in the spirit of Merton’s (1987) model of capital market equilibrium with incomplete information. We incorporate these sunk costs in standard discounted cash flow techniques and present the basic concepts of real options. The justification of information costs in real projects is based on the observation that R&D needs to be done before investment decisions. These costs account for all the expenses needed to get informed about an investment opportunity and the management of projects. This analysis extends the models in Bellalah (1999, 2001) for the valuation of real options within information uncertainty. We present valuation models and simulations for the values of common real options in the presence of shadow costs of incomplete information.Capital budgeting; Investment policy; Asset pricing; Option pricing; Information and market efficiency;