760,993 research outputs found
The Cost of Social Agents
In this paper we follow the BOID (Belief, Obligation, Intention, Desire) architecture to describe agents and agent types in Defeasible Logic. We argue that the introduction of obligations can provide a new reading of the concepts of intention and intentionality. Then we examine the notion of social agent (i.e., an agent where obligations prevail over intentions) and discuss some computational and philosophical issues related to it. We show that the notion of social agent either requires more complex computations or has some philosophical drawbacks
Strategy-Proof Facility Location for Concave Cost Functions
We consider k-Facility Location games, where n strategic agents report their
locations on the real line, and a mechanism maps them to k facilities. Each
agent seeks to minimize his connection cost, given by a nonnegative increasing
function of his distance to the nearest facility. Departing from previous work,
that mostly considers the identity cost function, we are interested in
mechanisms without payments that are (group) strategyproof for any given cost
function, and achieve a good approximation ratio for the social cost and/or the
maximum cost of the agents.
We present a randomized mechanism, called Equal Cost, which is group
strategyproof and achieves a bounded approximation ratio for all k and n, for
any given concave cost function. The approximation ratio is at most 2 for Max
Cost and at most n for Social Cost. To the best of our knowledge, this is the
first mechanism with a bounded approximation ratio for instances with k > 2
facilities and any number of agents. Our result implies an interesting
separation between deterministic mechanisms, whose approximation ratio for Max
Cost jumps from 2 to unbounded when k increases from 2 to 3, and randomized
mechanisms, whose approximation ratio remains at most 2 for all k. On the
negative side, we exclude the possibility of a mechanism with the properties of
Equal Cost for strictly convex cost functions. We also present a randomized
mechanism, called Pick the Loser, which applies to instances with k facilities
and n = k+1 agents, and for any given concave cost function, is strongly group
strategyproof and achieves an approximation ratio of 2 for Social Cost
A Faithful Distributed Implementation of Dual Decomposition and Average Consensus Algorithms
We consider large scale cost allocation problems and consensus seeking
problems for multiple agents, in which agents are suggested to collaborate in a
distributed algorithm to find a solution. If agents are strategic to minimize
their own individual cost rather than the global social cost, they are endowed
with an incentive not to follow the intended algorithm, unless the tax/subsidy
mechanism is carefully designed. Inspired by the classical
Vickrey-Clarke-Groves mechanism and more recent algorithmic mechanism design
theory, we propose a tax mechanism that incentivises agents to faithfully
implement the intended algorithm. In particular, a new notion of asymptotic
incentive compatibility is introduced to characterize a desirable property of
such class of mechanisms. The proposed class of tax mechanisms provides a
sequence of mechanisms that gives agents a diminishing incentive to deviate
from suggested algorithm.Comment: 8 page
Spatial Mobility in the Formation of Agent-Based Economic Networks
We extend the model of spatial social network formation of Johnson and Gilles (Review of Economic Design, 2000, 5, 273-299) by situating each economic agent within one of a set of discrete spatial locations and allowing agents to maximise the utility that they gain from their direct and indirect social contacts by relocating, in addition to forming or breaking social links. This enables the exploration of scenarios in which agents are able to alter the distance between themselves and other agents at some cost. Agents in this model might represent countries, firms or individuals, with the distance between a pair of agents representing geographical, social or individual differences. The network of social relationships characterises some form of self-organised persistent interaction such as trade agreements or friendship patterns. By varying the distance-dependent costs of relocation and maintaining social relationships we are able to identify conditions that promote the formation of spatial organisations and network configurations that are pairwise stable and efficient. We also examine the associated patterns in individual and aggregate agent behaviour. We find that both relative location and the order in which agents are allowed to act can drastically affect individual utility. These traits are found to be robust to random perturbations
The diplomat's dilemma: Maximal power for minimal effort in social networks
Closeness is a global measure of centrality in networks, and a proxy for how
influential actors are in social networks. In most network models, and many
empirical networks, closeness is strongly correlated with degree. However, in
social networks there is a cost of maintaining social ties. This leads to a
situation (that can occur in the professional social networks of executives,
lobbyists, diplomats and so on) where agents have the conflicting objectives of
aiming for centrality while simultaneously keeping the degree low. We
investigate this situation in an adaptive network-evolution model where agents
optimize their positions in the network following individual strategies, and
using only local information. The strategies are also optimized, based on the
success of the agent and its neighbors. We measure and describe the time
evolution of the network and the agents' strategies.Comment: Submitted to Adaptive Networks: Theory, Models and Applications, to
be published from Springe
Optimal Assignment of Durable Objects to Successive Agents
This paper analyzes the assignment of durable objects to successive generations of agents who live for two periods. The optimal assignment rule is stationary, favors old agents and is determined by a selectivity function which satisfies an iterative functional differential equation. More patient social planners are more selective, as are social planners facing distributions of types with higher probabilities for higher types. The paper also characterizes optimal assignment rules when monetary transfers are allowed and agents face a recovery cost, when agents' types are private information and when agents can invest to improve their types.Dynamic Assignment ; Durable Objects ; Revenue Management ; Dynamic Mechanism Design ; Overlapping Generations ; Promotions and Intertemporal Assignments
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