On the Construction of Substitutes

Gross substitutability is a central concept in Economics and is connected to important notions in Discrete Convex Analysis, Number Theory and the analysis of Greedy algorithms in Computer Science. Many different characterizations are known for this class, but providing a constructive description remains a major open problem. The construction problem asks how to construct all gross substitutes from a class of simpler functions using a set of operations. Since gross substitutes are a natural generalization of matroids to real-valued functions, matroid rank functions form a desirable such class of simpler functions. Shioura proved that a rich class of gross substitutes can be expressed as sums of matroid rank functions, but it is open whether all gross substitutes can be constructed this way. Our main result is a negative answer showing that some gross substitutes cannot be expressed as positive linear combinations of matroid rank functions. En route, we provide necessary and sufficient conditions for the sum to preserve substitutability, uncover a new operation preserving substitutability and fully describe all substitutes with at most 4 items

Substitute Valuations: Generation and Structure

Substitute valuations (in some contexts called gross substitute valuations) are prominent in combinatorial auction theory. An algorithm is given in this paper for generating a substitute valuation through Monte Carlo simulation. In addition, the geometry of the set of all substitute valuations for a fixed number of goods K is investigated. The set consists of a union of polyhedrons, and the maximal polyhedrons are identified for K=4. It is shown that the maximum dimension of the maximal polyhedrons increases with K nearly as fast as two to the power K. Consequently, under broad conditions, if a combinatorial algorithm can present an arbitrary substitute valuation given a list of input numbers, the list must grow nearly as fast as two to the power K.Comment: Revision includes more background and explanation

The Definition and Choice of Environmental Commodities for Nonmarket Valuation

Economic analyses of nature must somehow define the “environmental commodities” to which values are attached. This paper articulates a set of principles to guide the choice and interpretation of nonmarket commodities. We describe how complex natural systems can be decomposed consistent with what can be called “ecological production theory.” Ecological production theory--like conventional production theory--distinguishes between biophysical inputs, process, and outputs. We argue that a systems approach to the decomposition and presentation of natural commodities can inform and possibly improve the validity of nonmarket environmental valuation studies. We raise concerns about the interpretation, usefulness, and accuracy of benefit estimates derived without reference to ecological production theory.nonmarket valuation, stated preference, revealed preference, commodities, endpoints

Valuing lagoons using a meta-analytical approach: Methodological and practical issues

Among coastal areas, lagoons are probably one of the most active and sensitive areas. They provide numerous goods and services that are of value to people. As public goods, there are freely accessible but in counterpart there are more endangered than other areas. Conflict uses between activities inside and outside the lagoons or between occasional and regular users imply to implement the lagoons economic values in order to provide a useful management tool. Many studies have been driven in order to estimate the impacts of the different activities on water quality and the willingness to pay for a better environment. We collect 32 lagoon studies providing 67 value observations in order to present a comprehensive meta-analysis of the valuation literature. This method allows estimating a function that takes into account the sites characteristics, methodological variables and lagoons services. The estimation of a meta-analytic function proves that all theses kinds of variables are important for the calculus of values. Moreover, we precisely determine the influence of the different variables on the value. Performing the transfer, we find an average transfer error amount equal to 87% but a median transfer error equal to 24%. This result due to a very small number of aberrant values is interesting with one-fourth of the transfers showing errors lower to 10% and nearly three-fourth of the transfers present errors lower to 50%.

The Role of Auctions in Allocating Public Resources

This paper provides an economic framework within which to consider the effectiveness and limitations of auction markets. The paper looks at the use of auctions as a policy instrument and the effects of auction design on consumer interests, the efficient allocation of resources, and industry competitiveness.Australia; Research; Ascending-bid auction; Auctions; Bidders; Conservation funds; Descending-bid auction; Dutch auction; English auction; Environmental Management; First-price sealed-bid auction; Infrastructure; Markets; Oral auction; Outcry auction; Pollutant emission permits; Power supply contracts; Public resources; Radio- spectrum; Second-price sealed-bid auction Spectrum licences; Vickrey auction; Water rights;

Is Embedding Entailed in Consumer Valuation of Food Safety Characteristics?

Consumers’ preferences for food safety characteristics are investigated with particular focus on existence of an embedding effect. Embedding exists if consumer valuation of food safety is insensitive to scope. Two choice experiments have been conducted valuing food safety in respectively minced pork and chicken breasts, exemplified by avoiding human risks of Salmonella infections and strengthening the restrictions of using antibiotics in the pork production and in terms of avoiding human risks of Salmonella and Campylobacter infections respectively. The results showed no indications of an embedding effect between the food safety characteristics, in neither of the cases.Valuation, Choice Experiment, Market Goods, Food Safety, Embedding., Agricultural and Food Policy, Food Consumption/Nutrition/Food Safety,