A generic model for the monetary flow in multi-level marketing schemes for virtual goods, so called incentive management systems, is introduced and analysed. It is shown that such schemes can in principle be fair, and it is argued that they can be viably realised if the value of the distributed good is positive. It is shown how the monetary incentive a buyer receives through the scheme can be p...

ness of an element is the ratio of in-degrees over in-degrees plus out-degrees of the element, and ranges from 0 to l (Pieters et al. 1995). Elements with high abstractness scores are

The pastoral nomads of Iran, who had been able to achieve a “sustainable balance” between their environment and their economy throughout their history, are being held responsible for the degradation of the rangelands by the experts and state officials. The government of Iran has placed considerable resources into provision of advice and services to improve the natural resource status of Iranian...

The potential for high severity fires to affect changes in rangelands is considerable, and for this reason, assessing fire severity is critical. We explored fire severity modeling in rangelands by applying post-fire field observations to Satellite Pour l'Observation de la Terre 5 (SPOT 5) imagery using Classification Tree Analysis (CTA) techniques at two 2005 burns. The results of these analyse...

I characterize a finite additive utility representation for preferences over menus. The numbers of both positive and negative components in this representation are expressed explicitly in terms of preference. These expressions can be used to characterize models of temptation, perfectionism, context effects, and other phenomena. © 2008 Elsevier Inc. All rights reserved. JEL classification: D81