Results 1  10
of
15
Efficiency of ScalarParameterized Mechanisms
"... We consider the problem of allocating a fixed amount of an infinitely divisible resource among multiple competing, fully rational users. We study the efficiency guarantees that are possible when we restrict to mechanisms that satisfy certain scalability constraints motivated by large scale communica ..."
Abstract

Cited by 29 (2 self)
 Add to MetaCart
We consider the problem of allocating a fixed amount of an infinitely divisible resource among multiple competing, fully rational users. We study the efficiency guarantees that are possible when we restrict to mechanisms that satisfy certain scalability constraints motivated by large scale communication networks; in particular, we restrict attention to mechanisms where users are restricted to onedimensional strategy spaces. We first study the efficiency guarantees possible when the mechanism is not allowed to price differentiate. We study the worstcase efficiency loss (ratio of the utility associated with a Nash equilibrium to the maximum possible utility), and show that the proportional allocation mechanism of Kelly (1997) minimizes the efficiency loss when users are price anticipating. We then turn our attention to mechanisms where price differentiation is permitted; using an adaptation of the VickreyClarkeGroves class of mechanisms, we construct a class of mechanisms with onedimensional strategy spaces where Nash equilibria are fully efficient. These mechanisms are shown to be fully efficient even in general convex environments, under reasonable assumptions. Our results highlight a fundamental insight in mechanism design: when the pricing flexibility available to the mechanism designer is limited, restricting the strategic flexibility of bidders may actually improve the efficiency guarantee.
Efficient, strategyproof and almost budgetbalanced assignment
, 2007
"... Call a VickreyClarkeGroves (VCG) mechanism to assign p identical objects among n agents, feasible if cash transfers yield no deficit. The efficiency loss of such a mechanism is the worst (largest) ratio of the budget surplus to the efficient surplus, over all profiles of non negative valuations. T ..."
Abstract

Cited by 27 (3 self)
 Add to MetaCart
Call a VickreyClarkeGroves (VCG) mechanism to assign p identical objects among n agents, feasible if cash transfers yield no deficit. The efficiency loss of such a mechanism is the worst (largest) ratio of the budget surplus to the efficient surplus, over all profiles of non negative valuations. The optimal (smallest) efficiency loss � L(n, p) satisfies is strictly smaller or strictly �L(n, p) ≤ �L(n, { n 4
The price of anarchy of serial, average, and incremental cost sharing
 FORTHCOMING, ECONOMIC THEORY
, 2007
"... Users share an increasing marginal cost technology. A cost sharing method charges non negative cost shares covering costs. We look at the worst surplus (relative to the efficient surplus) in a Nash equilibrium of the demand game, where the minimum is taken over all convex preferences quasilinear in ..."
Abstract

Cited by 15 (4 self)
 Add to MetaCart
(Show Context)
Users share an increasing marginal cost technology. A cost sharing method charges non negative cost shares covering costs. We look at the worst surplus (relative to the efficient surplus) in a Nash equilibrium of the demand game, where the minimum is taken over all convex preferences quasilinear in cost shares. We compare average cost pricing and serial cost sharing, two budgetbalanced methods, and incremental cost sharing, a method collecting a budget surplus, that we count as a welfare loss. For any convex cost function, the average cost and serial methods guarantee a (relative) surplus no less than 1, where n is the number of n users. For some cost functions incremental cost sharing guarantees no positive gain. With quadratic costs, the surplus guaranteed by serial cost sharing is θ ( 1
Parameterized Supply Function Bidding: Equilibrium and Welfare
, 2007
"... Motivated by market design for electric power systems, we consider a model where a finite number of producers compete to meet an infinitely divisible but inelastic demand for the product. Each firm is characterized by a production cost that is convex in the output produced, and firms act as profit m ..."
Abstract

Cited by 13 (0 self)
 Add to MetaCart
(Show Context)
Motivated by market design for electric power systems, we consider a model where a finite number of producers compete to meet an infinitely divisible but inelastic demand for the product. Each firm is characterized by a production cost that is convex in the output produced, and firms act as profit maximizers. We consider a uniform price market design that uses supply function bidding [22]: firms declare the amount they would supply at any positive price, and a single price is chosen to clear the market. We are interested in evaluating the impact of price anticipating behavior both on the allocative efficiency of the market, and on the prices seen at equilibrium. We show that by restricting the strategy space of the firms to parameterized supply functions, we can provide upper bounds on both the inflation of aggregate cost at the Nash equilibrium relative to the socially optimal level, as well as the markup of the Nash equilibrium price above the competitive level: as long as N> 2 firms are competing, these quantities are both upper bounded by 1 + 1/(N − 2). This result holds even in the presence of asymmetric cost structure across firms. We also discuss several extensions, generalizations, and related issues.
Price of anarchy of cognitive mac games
 in IEEE Global Communications Conference (ICC
, 2009
"... Abstract — In this paper, we model and analyze the interactions between secondary users in a spectrum overlay cognitive system as a cognitive MAC game. In this game, each secondary user can sense (and transmit) one of several channels, the availability of each channel is determined by the activity o ..."
Abstract

Cited by 7 (5 self)
 Add to MetaCart
(Show Context)
Abstract — In this paper, we model and analyze the interactions between secondary users in a spectrum overlay cognitive system as a cognitive MAC game. In this game, each secondary user can sense (and transmit) one of several channels, the availability of each channel is determined by the activity of the corresponding primary user. We show that this game belongs to the class of congestion game and thus there exists at least one Nash Equilibrium. We focus on analyzing the worst case efficiency loss (i.e., price of anarchy) at any Nash Equilibrium of such a game. Closedform expressions of price of anarchy are derived for both symmetric and asymmetric games, with arbitrary channel and user heterogeneity. Several insights are also derived in terms of how to design a better cognitive radio system with less severe efficiency loss. I. BACKGROUND AND CONTRIBUTIONS
The price of anarchy of serial cost sharing and other methods
, 2005
"... Users share an increasing marginal cost technology. A method charges non negative cost shares covering costs. We look at the worst surplus (relative to the efficient surplus) in a Nash equilibrium of the demand game, where the minimum is taken over all convex preferences quasilinear in cost shares. ..."
Abstract

Cited by 4 (2 self)
 Add to MetaCart
(Show Context)
Users share an increasing marginal cost technology. A method charges non negative cost shares covering costs. We look at the worst surplus (relative to the efficient surplus) in a Nash equilibrium of the demand game, where the minimum is taken over all convex preferences quasilinear in cost shares. We compare two budgetbalanced methods, average cost pricing and serial cost sharing, and two methods collecting a budget surplus, marginal cost pricing and incremental cost sharing. In the latter case we count the budget surplus as a loss. For any convex cost function, the average cost and serial methods guarantee a (relative) surplus no less than 1, where n is the number of users. n Neither marginal cost pricing, nor incremental cost sharing guarantees any positive gain. With quadratic costs, the surplus guaranteed by serial cost sharing is O ( 1 log n) for the three other methods. This generalizes if the marginal cost is convex or concave, and its elasticity is bounded.
InterSession Network Coding with Strategic Users: A GameTheoretic Analysis of Network Coding
, 2009
"... A common assumption in the existing network coding literature is that the users are cooperative and do not pursue their own interests. However, this assumption can be violated in practice. In this paper, we analyze intersession network coding in a wired network using game theory. We assume that the ..."
Abstract

Cited by 1 (1 self)
 Add to MetaCart
A common assumption in the existing network coding literature is that the users are cooperative and do not pursue their own interests. However, this assumption can be violated in practice. In this paper, we analyze intersession network coding in a wired network using game theory. We assume that the users are selfish and act as strategic players to maximize their own utility, which leads to a resource allocation game among users. In particular, we study network coding with strategic users for the wellknown butterfly network topology where a bottleneck link is shared by several network coding and routing flows. We prove the existence of a Nash equilibrium for a wide range of utility functions. We also show that the number of Nash equilibria can be large (even infinite) for certain choices of system parameters. This is in sharp contrast to a similar game setting with traditional packet forwarding where the Nash equilibrium is always unique. We then characterize the worstcase efficiency bounds, i.e., the PriceofAnarchy (PoA), compared to an optimal and cooperative network design. We show that by using a novel discriminatory pricing scheme which charges encoded and forwarded packets differently, we can improve the PoA in comparison with the case where a single pricing scheme is being used. However, regardless of the discriminatory pricing scheme being used, the PoA is still worse than for the
Fair Allocation of Production Externalities: Recent Results
, 2005
"... Faculté des arts et des sciences ..."