We study techniques to enforce and provision differentiated service levels in Computational Grid systems. The Grid offers simplified provisioning of peak-capacity for applications with computational requirements beyond local machines and clusters, by sharing resources across organizational boundaries. Current systems have focussed on access control, i.e., managing who is allowed to run applicat...

objective: water scarcity is a growing global problem and increasing population pressures, living standards and the growing demand for environmental quality have evoked all the governments to represent better solutions about water resources management. in addition, there are growing political ties for reducing water use in agriculture that follow enough environmental benefits and increase the w...

BACKGROUND Interaction in clinical trials presents challenges for design and appropriate sample size estimation. Here we considered interaction between treatment assignment and a dichotomous prognostic factor with a continuous outcome. Our objectives were to describe differences in power and sample size requirements across alternative distributions of a prognostic factor and magnitudes of the i...

Policy-makers targeting reduction in greenhouse gas (GHG) emissions have a variety of instruments at their disposal (emission taxes excluded). Policies implemented thus far such as the Kyoto protocol, EU’s Emission Trading Scheme, and the Regional Greenhouse Gas Initiative in the US north-east, suggest that the preferred instrument is an emission quota per polluter. The prinicipal activity targ...

The Struggle over Migration Policy ∗ In this paper we analyze the endogenous determination of migration quota viewing it as an outcome of a two-stage political struggle between two interest groups: those in favor and those against the proposed migration quota. We first compare the proposed policies of the two interest groups under random behavior of the government, with and without lobbying. Th...

We adopted an economic analysis to evaluate and discuss the management of conservation and commercial exploitation of whales. In particular, the paper starts from the recent proposal to create and implement a quota market for whale trading and attempts to address and develop selected economic issues, in order to move towards understanding the economics of whales. We can summarize our findings i...

The widely discussed ‘discursive dilemma’shows that majority voting in a group of individuals on logically connected propositions may produce irrational collective judgments. We generalize majority voting by considering quota rules, which accept each proposition if and only if the number of individuals accepting it exceeds a given threshold, where di¤erent thresholds may be used for di¤erent pr...

Abstract This paper establishes relationships between static Nash equilibria and dynamic Markov perfect equilibria of tariff and quota retaliation games. In supermodular games where tariffs are strategic complements, the steady state of every, symmetric Markov perfect equilibrium must have lower tariffs than in the static equilibrium. If tariffs are strategic substitutes, tariffs in the dynamic...

This paper considers a dynamic common agency model of natural resource harvest quota regulation in which both conservationists and harvesters vie to influence the regulator’s quota allocations as well as the choice of regulator. Conservationists tend to benefit from the adoption of regulation since the regulator will reduce the aggregate harvest quota relative to the unregulated equilibrium. Ha...