by reducing the back-projection in the root process by the relative time of ltering and backprojection, an utilization of 81.8% was achieved. Symmetric Multiprocessor Computations were done on a DEC AlphaServer 2000 4/233. This machine is an SMP with 2 processors , and 256 MB of RAM. The parallel implementation with complete load balancing was used. The serial version ran in 684.2 seconds and t...

In many European states such as Spain and Italy there has been a significant growth of organic utilizable surface as a consequence of both a change in the model of agricultural production and also in order to satisfy arising demand of organic food. The purpose of this research was to investigate the level of technical, allocative and economic efficiency in Italian olive farms with two different...

In this paper, we model production technology in a state-contingent framework. We assume that all the firms use the same stochastic technology, but they may have different risk attitudes and information sets, and ex post they may operate in different production environments. Firms maximise ex ante their preference function subject to a stochastic technology constraint; in other words, they are ...

We introduce contingent auction mechanisms, which is a superset of combinatorial auctions, and where bidders submit bids on packages that are contingent on the whole nal assignment. Without externalities, the Vickrey and the Ausubel-Milgrom Proxy Auction are both robust if items are perceived as substitutes. Such an equivalence between those formats may not hold with externalities and the analo...

We study efficient, Bayes-Nash incentive compatible mechanisms in a social choice setting that allows for informational and allocative externalities. We show that such mechanisms exist only if a congruence condition relating private and social rates of information substitution is satisfied. If signals are multidimensional, the congruence condition is determined by an integrability constraint, a...

We study e¢cient, Bayes-Nash incentive compatible mechanisms in a social choice setting that allows for informational and allocative externalities. We show that such mechanisms exist only if a congruence condition relating private and social rates of information substitution is satis...ed. If signals are multidimensional, the congruence condition is determined by an integrability constraint, an...

This paper develops a test for Pareto-elliciency in the local public sector using the analytical result that aggregate property value is maximized at the public output level which satisfies the Samuelson condition for efficiency. By using cross-section data, it is possible to deduce whether a representative community provides its public goods in a property-value-maximizing (and hence efficient)...

We propose a new measure of allocative efficiency based on unrealized increases in aggregate productivity growth. We show that the difference in the value of the marginal product of an input and its marginal cost at any plant the plant-input “gap” is exactly equal to the change in aggregate output that would occur if that plant changed that input’s use by one unit. The mean absolute gap across ...