Intertemporal and Spatial Location of Disposal Facilities

The optimal capacity and location of a sequence of landfills are studied, and the interactions between both decisions are pointed out. Deciding the capacity of a landfill has some spatial implications, because it effects the feasible region for the rest of the landfills, and some temporal implications because the capacity determines the lifetime of the landfill and hence the instant of time where the next landfills will need to be constructed. Some general mathematical properties of the solution are provided and interpreted from an economic point of view. The resulting problem turns out to be nonconvex and, therefore, it can not be solved by conventional optimization techniques. Some global optimization methods are used to solve the problem in a particular case to illustrate the behavior of the solution depending on the parameter values.Landfilling, Optimal Capacity, Optimal Location, Global Optimization.

Robust Stylized Facts on Comovement for the Spanish Economy

In this article we further develop the suggestion of obtaining stylized facts on comovement on the basis of prewhitened time series proposed in André, Pérez and Martín (2002). Firstly, we show some examples on the robustness of the method. Secondly, we test the relevance of such a proposal by revisiting some of the existing stylized facts on comovement for the Spanish economy in Dolado, Sebastián and Vallés (1993).Stylized Facts, Comovement, Cross Correlation Function, HP-Filter, Prewhitening

OPTIMAL SUBSTITUTION OF RENEWABLE AND NONRENEWABLE NATURAL RESOURCES IN PRODUCTION

A theoretical model is presented in order to study the optimal combination of natural resources, used as inputs, taking into account their natural growth ability and the technical possibilities of input substitution. The model enables us to consider renewable resources, nonrenewable, or both. The relative use of resources evolves through time according to the difference between both resources' natural growth and technological flexibility, as measured by the elasticity of substitution of the production function. Output evolves according to a version of the traditional Keynes-Ramsey rule, where the marginal productivity of capital is substituted by the ''marginal productivity of natural capital'', that is a combination of both resources' marginal growth weighted by each resource return in production.Renewable Resources, Nonrenewable Resources, Production, Optimal Control.

On natural resource substitution

We present a simple dynamic model to get some key insights about the substitution of renewable for nonrenewable resources in production and the consequences for sustainability. We highlight the role of the elasticity of substitution (technological component) to determine the adjustment of every sector as a response to scarcity and growing ability of resources (environmental component). Sometimes, the model predicts a smooth substitution of renewable resources for nonrenewables, but this process could work in the opposite direction if renewable resources are temporarily beyond their maximum sustainable yield, so that their marginal natural growth is negative. If substitution possibilities are high enough, it may be optimal to suspend the extraction of a resource, for example, to allow for regeneration of the biomass. We show analytically that a production process is more likely to be sustainable the more heavily it depends on renewable, rather than nonrenewable resources.Renewable resources, Nonrenewable resources, Production, Optimal control.

A Duality Procedure to Elicit Nonlinear Multiattribute Utility Functions.

The practical implementation of the Multiattribute Utility Theory is limited, partly for the lack of operative methods to elicit the parameters of the Multiattribute Utility Function, particularly when this function is not linear. As a consequence, most studies are restricted to linear specifications, which are easier to estimate and to interpret. We propose an indirect method to elicit the parameters of a nonlinear utility function to be compatible with the actual behaviour of decision makers, rather than with their answers to direct surveys. The idea rests on approaching the parameter estimation problem as a dual of the decision problem and making the observed decisions to be compatible with a rational decision making process.Multiple-Criteria Analysis, Multi-Attribute Utility Function, Simulation, Agriculture.

On the equivalence between compromise programming and the use of composite compromise metrics.

This paper analyzes the relationship between Compromise Programming and a close relative called Composite Programming that is based on the use of composite metrics. More specifically, it focuses on the possibility that the results of Compromise Programming are equivalent to those obtained with a particular case of Composite Programming in which a linear combination between the two bounds of the compromise set is established. Several situations, depending on the number of criteria involved and the mathematical structure of the efficient set, are studied. The most relevant result is obtained when two criteria are involved and the efficient set is continuously differentiable. In this case, it is possible to find a unique equivalent value of the control parameter in Composite Programming for each metric in Compromise Programming. It is remarked that this particular case is very relevant in many economic scenarios. On the other hand, it turns out that the equivalence between both approaches can not be extended to the case with more than two criteria.Compromise programming, composite metric, p-norms, economic optimization.

Efficient Economic and Environmental Policies Combining Multicriteria Techniques and General Equilibrium Modelling.

In this paper we propose an analytical approach to obtain so-called efficient policies in terms of environmental and economic objectives. A policy is said to be efficient if any environmental or economic achievement is obtained with the minimum possible detriment to other relevant objectives. We apply this concept obtain the minimum possible environmental impact for a given growth rate or, symmetrically, the maximum economic growth for a given amount of polluting emissions. We present an application to Spanish economy with 2000 data using a Computable General Equilibrium model. We evaluate the efficiency of the observed policy and give some policy recommendations. Finally, we give an idea about how to enlarge the analysis by including additional objectives.Efficient policies, Computable general equilibrium, multicriteria decision making.

Multicriteria Policy Making. Defining Efficient Policies in a General Equilibrium Model

We propose to model policy making as a multicriteria problem and solve it using suitable multicriteria techniques in connection with some structural economic model to represent optimal policy making and to get useful policy recommendations. By using a multiobjective approach combined with a Computable General Equilibrium model, we propose the concept of efficient policy and calculate the set of efficient policies for the Spanish economy in an empirical exercise. This approach allows us to quantify the trade-off between growth and inflation, to measure the efficiency of the actually applied fiscal policy and to get some plausible modifications that could foster policy efficiency in practice.Public Policy, Multicriteria Decision Making, Efficient Frontier, Computable General Equilibrium Model.

COMPUTING ROBUST STYLIZED FACTS ON COMOVEMENT

We propose an alternative method of obtaining stylized facts on comovement, based on the cross-correlation function of the prewhitened time series, which only depends on the purely stochastic components of the series and the cross efects between them. This approach has the property of being robust to the filtering procedure and hence to the cicle definition. The usual approach consists of obtaining the cross-correlation function of filtered variables, which reflect a mixture of both the existing cross-correlation between the variables and the autocorrelation structure of each of them. The autocorrelation structure, in turn, crucially depends on the filtering procedure. The relevance of such an approach is tested by revisiting some of the facts reported by Kydland and Prescott (1990).Prewhitening, Business Cycle, Stylized Facts, Comovement.

Using a modified DEA model to estimate the importance of objectives. An application to agricultural economics.

This paper shows a connection between Data Envelopment Analysis (DEA) and the methodology proposed by Sumpsi et al. (1997) to estimate the weights of objectives for decision makers in a multiple attribute approach. This connection gives rise to a modified DEA model that allows to estimate not only efficiency measures but also preference weights by radially projecting each unit onto a linear combination of the elements of the payoff matrix (which is obtained by standard multicriteria methods). For users of Multiple Attribute Decision Analysis the basic contribution of this paper is a new interpretation of the methodology by Sumpsi et al. (1997) in terms of efficiency. We also propose a modified procedure to calculate an efficient payoff matrix and a procedure to estimate weights through a radial projection rather than a distance minimization. For DEA users, we provide a modified DEA procedure to calculate preference weights and efficiency measures which does not depend on any observations in the dataset. This methodology has been applied to an agricultural case study in Spain.Multicriteria Decision Making, Goal Programming, Weights, Preferences, Data Envelopment Analysis.