Equivalence of Resource/Opportunity Egalitarianism and Welfare Egalitarianism in Quasilinear Domains

We study the allocation of indivisible goods when monetary transfers are possible and preferences are quasilinear. We show that the only allocation mechanism (upto Pareto-indifference) that satisfies the axioms supporting resource and opportunity egalitarianism is the one that equalizes the welfares. We present alternative characterizations, and budget properties of this mechanism and discuss how it would ensure fair compensation in government requisitions and condemnations.egalitarianism, egalitarian-equivalence, no-envy, distributive justice, allocation of indivisible goods and money, fair auctions, the Groves mechanisms, strategy-proofness, population monotonicity, cost monotonicity, government requisitions, eminent domain

Characterizing Welfare-egalitarian Mechanisms with Solidarity When Valuations are Private Information

In the problem of assigning indivisible goods and monetary transfers, we characterize welfare-egalitarian mechanisms (that are decision-efficient and incentive compatible) with an axiom of solidarity under preference changes and a fair ranking axiom of order preservation. This result is in line with characterizations of egalitarian rules with solidarity in other economic models. We also show that we can replace order-preservation with egalitarian-equivalence or no-envy (on the subadditive domain) and still characterize the welfare-egalitarian class. We show that, in the model we consider, the welfare-egalitarian mechanisms appear to be the best candidates to satisfy several different fairness and solidarity requirements as well as generating bounded deficits.egalitarianism, solidarity, order preservation, egalitarian-equivalence, no-envy, distributive justice, NIMBY problems, imposition of tasks, allocation of indivisible (public) goods and money, the Groves mechanisms, strategy-proofness

Welfare Bounds in a Growing Population

We study the allocation of collectively owned indivisible goods when monetary transfers are possible. We restrict our attention to incentive compatible mechanisms which allocate the goods efficiently. Among these mechanisms, we characterize those that respect welfare lower bounds. The main characterization involves the identical-preferences lower-bound: each agent should be at least as well off as in an hypothetical economy where all agents have the same preference as hers, no agent envies another, and the budget is balanced. This welfare lower-bound grants agents equal rights/responsibilities over the jointly owned resources but insures agents against the heterogeneity in preferences. We also study the implications of imposing variable population axioms together with welfare bounds.collective ownership, allocation of indivisible goods and money, NIMBY problems, imposition of tasks, the Groves mechanisms, the identical-preferences lower-bound, individual rationality, the stand-alone lower-bound, k-fairness, population monotonicity

Egalitarian-equivalent Groves Mechanisms in the Allocation of Heterogeneous Objects

We study the problem of allocating objects when monetary transfers are possible. We are interested in mechanisms that allocate the objects in an efficient way and induce the agents to report their true preferences. Within the class of such mechanisms, first we characterize egalitarian-equivalent mechanisms. Then, we add a bounded-deficit condition and characterize the corresponding class. Finally, we investigate the relations between egalitarian-equivalence and other fairness notions such as no-envy.fairness, allocation of indivisible goods and money, task assignments, strategy-proofness, the Vickrey-Clarke-Groves mechanisms, egalitarian-equivalence, no-envy, order preservation

Axiomatizing Political Philosophy of Distributive Justice: Equivalence of No-envy and Egalitarian-equivalence with Welfare-egalitarianism

We characterize welfare-egalitarian mechanisms (that are decision-efficient and incentive compatible) with the two fundamental axioms of fairness: no-envy and egalitarian-equivalence. We consider cases where agents have equal rights over external world resources but are individually responsible for their preferences/costs. Our characterization answers the political philosophy question of what kind of welfare differentials allowed if we respect private ownership rights over self and public ownership over external world. We also relate no-envy and egalitarian-equivalence to "equality of what" debate and build a link between resource and opportunity egalitarianism, and welfare-egalitarianism.egalitarianism, egalitarian-equivalence, no-envy, distributive justice, equality of opportunity, resource egalitarianism, private ownership of the self and public ownership of external world, NIMBY problems, allocation of indivisible goods and money, discrete public goods, strategy-proofness.

Undominated Groves Mechanisms

The family of Groves mechanisms, which includes the well-known VCG mechanism (also known as the Clarke mechanism), is a family of efficient and strategy-proof mechanisms. Unfortunately, the Groves mechanisms are generally not budget balanced. That is, under such mechanisms, payments may flow into or out of the system of the agents, resulting in deficits or reduced utilities for the agents. We consider the following problem: within the family of Groves mechanisms, we want to identify mechanisms that give the agents the highest utilities, under the constraint that these mechanisms must never incur deficits. We adopt a prior-free approach. We introduce two general measures for comparing mechanisms in prior-free settings. We say that a non-deficit Groves mechanism $M$ {\em individually dominates} another non-deficit Groves mechanism $M'$ if for every type profile, every agent's utility under $M$ is no less than that under $M'$, and this holds with strict inequality for at least one type profile and one agent. We say that a non-deficit Groves mechanism $M$ {\em collectively dominates} another non-deficit Groves mechanism $M'$ if for every type profile, the agents' total utility under $M$ is no less than that under $M'$, and this holds with strict inequality for at least one type profile. The above definitions induce two partial orders on non-deficit Groves mechanisms. We study the maximal elements corresponding to these two partial orders, which we call the {\em individually undominated} mechanisms and the {\em collectively undominated} mechanisms, respectively.Comment: 34 pages. To appear in Journal of AI Research (JAIR

A Bayesian Incentive Compatible Mechanism for Fair Division

We consider the problem of fairly allocating one indivisible object when monetary transfers are possible, and examine the existence of Bayesian incentive compatible mechanisms to solve the problem. We propose a mechanism that satisfies envy-freeness, budget balancedness, and Bayesian incentive compatibility. Further, we establish the uniqueness of the mechanism under an order additivity condition. This result contrasts well with various results on the incompatibility between efficiency and ex post incentive compatibility.

Characterizations of Pareto-efficient, fair, and strategy-proof allocation rules in queueing problems

A set of agents with possibly different waiting costs have to receive the same service one after the other. Efficiency requires to maximize total welfare. Equity requires to at least treat equal agents equally. One must form a queue, set up monetary transfers to compensate agents having to wait, and not a priori arbitrarily exclude agents from positions. As one may not know agents’ waiting costs, they may have no incentive to reveal them. We identify the only rule satisfying Pareto-efficiency, a weak equity axiom as equal treatment of equals in welfare or symmetry, and strategy-proofness. It satisfies stronger axioms, as no-envy and anonymity. Further, its desirability extends to related problems. To obtain these results, we prove that even non-single-valued rules satisfy Pareto-efficiency of queues and strategy-proofness if and only if they select Pareto-efficient queues and set transfers in the spirit of Groves (1973). This holds in other problems, provided the domain of quasi-linear preferences is rich enough.queueing problems, efficiency, fairness, strategy-proofness

The Reverse Auction: A New Approach to Experimental Auction Valuation

I propose an alternative approach to auction valuation in which participants indicate the quantity they wish to buy at a series of prices, with the understanding that one will be randomly chosen as the binding price. This technique allows researchers to estimate entire demand curves as well as own-price elasticities.Demand and Price Analysis,