The case for institutions Agents and Institutions Real-world examples Case Studies CM30174 Intelligent Agents Semester 1, 2010–11 Marina De Vos, Julian Padget Institutions and Norms / version 0.4 November 22, 2010 De Vos/Padget (Bath/CS) CM30174/Institutions November 22, 2010 1 / 47 The case for institutions Agents and Institutions Real-world examples Case Studies Content The case for institutions 1 Agents and Institutions 2 Real-world examples 3 Case Studies 4 Case study 1: electricity markets in the UK Case study 2: complementary currencies De Vos/Padget (Bath/CS) CM30174/Institutions November 22, 2010 2 / 47 The case for institutions Agents and Institutions Real-world examples Case Studies Content The case for institutions 1 Agents and Institutions 2 Real-world examples 3 4 Case Studies De Vos/Padget (Bath/CS) CM30174/Institutions November 22, 2010 3 / 47
The case for institutions Agents and Institutions Real-world examples Case Studies Context From Game Theory to Institutions: GT enables strategic analysis ... but games are (relatively) simple participants make bounded rational choices Negotiation and Contract Net: Typically one-shot encounters Components in more complex scenarios More complex frameworks with stronger guarantees: Coalition: A group of agents, different skills Virtual Organization: A group of agents, subject to a particular, agreed regulatory framework Virtual Institution: A pattern of actions, sanctions, roles and goals De Vos/Padget (Bath/CS) CM30174/Institutions November 22, 2010 4 / 47 The case for institutions Agents and Institutions Real-world examples Case Studies Why Institutions are Essential Unconstrained behaviour is not freedom (Multiple) Institutions abstract the interaction frameworks needed for constraining behaviour Agents can negotiate institutional change Institutions can be repositories of emergent behaviour Institutions can be formalized and reasoned about with limited computational resources De Vos/Padget (Bath/CS) CM30174/Institutions November 22, 2010 5 / 47 The case for institutions Agents and Institutions Real-world examples Case Studies Is Price Everything? Market extreme: Everything has a price ∃ f : A 1 × ... × A n → R + that is f ( a 1 , ..., a n ) → p Hence, the only necessary mechanism is the auction ... and it can be analyzed Social extreme: Multi-attribute decision making Social and environmental factors Variety of complex mechanisms ... but it can only be simulated Analysts vs. Empiricists Institutions unite these extremes Enable analytical and empirical approaches De Vos/Padget (Bath/CS) CM30174/Institutions November 22, 2010 6 / 47
The case for institutions Agents and Institutions Real-world examples Case Studies Requirements Engineering System evolution: closed → semi-open → open (Good) governance: evaluating risks and monitoring compliance How can component actions be regulated without compromising their integrity or revealing information? Contracts: service level agreements Monitoring/Auditing framework Roles, powers, permissions, authentication Virtual ↔ physical world interaction: counts-as Institutions are a non-invasive way to constrain software components in open architectures De Vos/Padget (Bath/CS) CM30174/Institutions November 22, 2010 7 / 47 The case for institutions Agents and Institutions Real-world examples Case Studies Common Goods Common goods: “The Tragedy of the Commons” [Hardin, 1968] — an important class of goods that conventional markets cannot (?) handle A resource is shared None has an incentive to restrict their consumption Yet over-consumption will exhaust the resource Examples: water, pasture, fish, bandwidth A generic problem without a generic solution. For a detailed set of case studies see “Governing the Commons” by Elinor Ostrom [Ostrom, 1990] De Vos/Padget (Bath/CS) CM30174/Institutions November 22, 2010 8 / 47 The case for institutions Agents and Institutions Real-world examples Case Studies Institutions: Quality without a Name Christopher Alexander [Alexander, 1980]: architecture — the design of habitable spaces Effective social institutions — social interaction spaces are no different from habitable spaces In “Social Laws” [Shoham and Tennenholtz, 1995] the authors identify a more limited objective: Laws which guarantee the successful co-existence of multiple programs and programmers” Task-oriented domains [Rosenschein and Zlotkin, 1994]: achievement vs. maintenance tasks ≡ “good” final states arising from norm-compliant agent actions De Vos/Padget (Bath/CS) CM30174/Institutions November 22, 2010 9 / 47
The case for institutions Agents and Institutions Real-world examples Case Studies Content The case for institutions 1 Agents and Institutions 2 Real-world examples 3 Case Studies 4 De Vos/Padget (Bath/CS) CM30174/Institutions November 22, 2010 10 / 47 The case for institutions Agents and Institutions Real-world examples Case Studies What is an Agent? An agent is a computer system capable of autonomous action in some environment: the situated agent. AGENT sense act ENVIRONMENT De Vos/Padget (Bath/CS) CM30174/Institutions November 22, 2010 11 / 47 The case for institutions Agents and Institutions Real-world examples Case Studies What are Multi -Agent Systems? An agent can be more useful in the context of others: Can concentrate on tasks within competence Can delegate other tasks Can use ability to communicate, coordinate, negotiate AGENT 2 AGENT 1 AGENT 3 sense act act sense sense act ENVIRONMENT De Vos/Padget (Bath/CS) CM30174/Institutions November 22, 2010 12 / 47
The case for institutions Agents and Institutions Real-world examples Case Studies What are Multi -Agent Systems? So, a MAS is a collection of interacting agents? No: Needs meaningful ways for agents to interact Needs organizational framework Needs identification of roles, responsibilities, permissions Needs to be verified Needs to be validated De Vos/Padget (Bath/CS) CM30174/Institutions November 22, 2010 13 / 47 The case for institutions Agents and Institutions Real-world examples Case Studies Agents and Organizations Agents ⇐ ⇒ Autonomy Agents are motivated by their own objectives, beliefs... ⇒ may take up organizational role if it serves their purposes Organization ⇐ ⇒ Regulation Organizations (too) have their own purpose Exist independently of the agents populating it Fundamental tension De Vos/Padget (Bath/CS) CM30174/Institutions November 22, 2010 14 / 47 The case for institutions Agents and Institutions Real-world examples Case Studies Need for organization Do agents need organizations? Do agents need to know/reason about the organization? Do MAS need organizations? Interaction in MAS cannot be based on communication alone MAS engineering requires high level agent-independent abstractions Explicit social concepts, defining the society in which agents participate De Vos/Padget (Bath/CS) CM30174/Institutions November 22, 2010 15 / 47
The case for institutions Agents and Institutions Real-world examples Case Studies The agent perspective Ensure a better integration of agents with system, In order better to adapt to change Delegation of task/beliefs between agents � coalitions (organizational) structures that need representation to enable their exploitation Despite or thanks to: Multiple limitations: cognitive, physical, temporal, institutional Autonomy of agents The different organizations in which agents participate De Vos/Padget (Bath/CS) CM30174/Institutions November 22, 2010 16 / 47 The case for institutions Agents and Institutions Real-world examples Case Studies The MAS perspective Need to ensure a global behaviour at the MAS level: In terms of cooperation, collaboration, ... To be sure the global system goals, or those of an instance of a collective are achieved Need to represent observed patterns of interaction Despite or thanks to: Multiple limitations: cognitive, physical, temporal, institutional Autonomy of agents Descriptive of prescriptive view De Vos/Padget (Bath/CS) CM30174/Institutions November 22, 2010 17 / 47 The case for institutions Agents and Institutions Real-world examples Case Studies What is an Institution? A set of rules: capable of describing correct and incorrect action, obligations acquired through correct action and sanctions levied for incorrect action while maintaining a record through its internal state. An institution is a set of rules that interprets some but not necessarily all of an agent’s actions as correct or incorrect within that context: the norm-regulated agent. AGENT sense act sense INSTITUTION act sense act ENVIRONMENT De Vos/Padget (Bath/CS) CM30174/Institutions November 22, 2010 18 / 47
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