Welfare Engineering in Practice ESAW 2004

Welfare Engineering in Practice: On the Variety of Multiagent Resource

Allocation Problems

Yann Chevaleyre1, Ulle Endriss2, Sylvia Estivie1

and Nicolas Maudet1

(1)LAMSADE, Univ. Paris IX-Dauphine(2)Dept. of Computing, Imperial College London

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Welfare Engineering in Practice ESAW 2004

Introduction• Recurring problems like E-auctions, patrol …

– Similarities between these problems ? Not exploited yet…

– Formalize this similarities for a category of problem : Resource allocation problem

• Why???– A lot of theoretical result for resource allocation– Possibility to develop a platform

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Welfare Engineering in Practice ESAW 2004

Talk Overview

• Welfare Engineering• Designer scope• Resource Allocation Framework• Example Applications• Criteria• Conclusion

Y. Chevaleyre, U. Endriss, S. Estivie, N. Maudet 4

Welfare Engineering in Practice ESAW 2004

Welfare Engineering

• Social welfare ordering (quality of the solution)• Social interaction mechanism (to arrive at a solution)• Behaviour profiles (interaction mechanism)

How we can make agents negotiate socially optimal outcomes?

Socially optimal allocation of resources

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Welfare Engineering in Practice ESAW 2004

Talk Overview

• Welfare Engineering• Designer scope• Resource Allocation Framework• Example Applications• Criteria• Conclusion

Y. Chevaleyre, U. Endriss, S. Estivie, N. Maudet 6

Welfare Engineering in Practice ESAW 2004

The Problem of the Designer Scope

• [Wurman et al 02]

• Agent scope

• Mechanism scope

• System scope

• Proprietor role

• End-user role

Agent

Which agent does designer control?

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Welfare Engineering in Practice ESAW 2004

Talk Overview

• Welfare Engineering• Designer scope• Resource Allocation Framework• Example Applications• Criteria• Conclusion

Y. Chevaleyre, U. Endriss, S. Estivie, N. Maudet 8

Welfare Engineering in Practice ESAW 2004

• Finite set of agents A and finite set of discrete resources R• An allocation A is a partitioning of R amongst the agents in A

• Every agent i A has a utility function ui(A)

Resource Allocation by Negotiation

R

A

A

u1(A)u2(A)

u3(A)u4(A)

1 2

3 4

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Welfare Engineering in Practice ESAW 2004

Social Welfare

Social welfare is tied to the welfare

of a society’s weakest member

• Envy-freeness social welfare

• Egalitarian social welfare

• Utilitarian social welfareAnything that increases average utility

is taken to be socially beneficial

Majoring the well being of a society

There is zero probability of having an

agent envying somebody elseResearch issue : the impact of individual utility on social welfare

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Welfare Engineering in Practice ESAW 2004

Our framework (1/2)• Monetary payments

– Deal couple with monetary side payment – Payment function

• Limited money

• Approximating flows– Representation of continuous resources (water,

energy, …)

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Welfare Engineering in Practice ESAW 2004

Our framework (2/2)• Roles

– Sellers– Buyers – …

• Protocol restrictions– Restrictions on the negotiation protocol

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Welfare Engineering in Practice ESAW 2004

Talk Overview

• Welfare Engineering• Designer scope• Resource Allocation Framework• Example Applications• Criteria• Conclusion

Y. Chevaleyre, U. Endriss, S. Estivie, N. Maudet 13

Welfare Engineering in Practice ESAW 2004

Examples of Applications (1/3)• Multiagent Patrolling (1/2)

– The multiagent patrolling problem: how should agents move around an area such that every part of the area is visited the most often ?

– Goal : find strategies which minimize the time between 2 visit on each node ? ?

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Welfare Engineering in Practice ESAW 2004

Examples of Applications (1/3)• Multiagent Patrolling (2/2)

– Multiagent patrolling applies to: • Multi-robot applications (intrusion detection, cleaning team of robots,

delivery)• Video-games (in warcraft-like games, doom-like, …)• Military application (surveillance, tracking intruders)• Internet applications

– Resources : each node– Utility of each agent : how well it patrols over the node it

owns– Resource allocation : agent can exchange nodes in order

to maximize his patrolling performance

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Welfare Engineering in Practice ESAW 2004

Examples of Applications (2/3)

• Allocation of satellite resources [Lemaitre et al 03]

Agents send observation request

Resources initially held by the virtual proprietor

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Welfare Engineering in Practice ESAW 2004

Examples of Applications (3/3)

• E-Auctions– Different kinds of e-auction

• B2C (Business to Consumer) : antique dealer • C2C (Consumer to Consumer) : eBay like• B2B (Business to Business) : FCC, fairmarket…

– Similarities and differences :but all could be represented with a model of resource allocation.

– Roles : sellers and buyers

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Welfare Engineering in Practice ESAW 2004

Talk Overview

• Welfare Engineering• Designer scope• Resource Allocation Framework• Example Applications• Criteria• Conclusion

Y. Chevaleyre, U. Endriss, S. Estivie, N. Maudet 18

Welfare Engineering in Practice ESAW 2004

Criteria for a Social Welfare Selection (1/2)

Proprietor gain– Utility-dependent

• Example : tax on gain

• Example of application uses it : Multiagent Patrolling

– Transaction-dependent• Example : tax on each transaction

• Example of application uses it : e-auctions

– Membership-dependent• Example : Entrance fees

• Example of application uses it : Satellite allocation, e-auctions

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Welfare Engineering in Practice ESAW 2004

Criteria for a Social Welfare Selection (2/2)

Application dynamics Between a run

• Possibility for an application to run several times– Yes : Satellite application, C2C e-auctions

– No : FCC e-auctions

• If yes, whether and how the characteristics could be modified between runs?

– C2C e-auctions : users may be different

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Conclusion

• Multiagent resource allocation : A powerful paradigm

• The first idea of social welfare choice in not necessarily the better. [Guttman, Maes 99]

Toward a test platform

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References [Guttman, Maes 99] R.H. Guttman and P. Maes. Agent Mediated

integrative negotiation for retail electronic commerce. In Agent Mediated Electronic Commerce, 1999.

[Lemaitre et al 03] M. Lemaitre, G. Verfaillie, H. Fargier, J. Lang, N. Bataille and J.M. Lachiver. Equitable allocation of earth observing satellites resources. In Proc of the 5th ONERA-DLR Aerospace Symposium (ODAS’03), 2003.

[Wurman et al 02] P.R. Wurman, M.P. Wellman, and W.E. Walsh. Specifing rules for electronic auctions. AI Magazine, 23(3):15-23, 2002.