Information Sharing Using an Electronic Marketplace

1
Information Sharing Usingan Electronic
Marketplace

• David Montana, Alice Leung and Marshall Brinn
• BBN Technologies

2
Overview

• Motivation
• Background
• Information sharing market
• A game Find the Ring
• Experiments
• Conclusions

3
Information Sharing Requirements

• Lack of information sharing played an important
  part of intelligence failure prior to 9/11
• pieces of information existed, but could not
  piece them together
• Obstacles to information sharing
• inertia of separation (cultural and
  technological)
• threats to security and privacy
• need to know and paper trail have provided
  safeguards against too-wide dissemination
• example of problem Robert Hanssen and FBI
  database
• Required ability to share critical information
  across organizations fluidly as needed to detect
  terrorist plots but not too widely
• Proposed solution well-regulated and restricted
  electronic market for buying and selling of
  intelligence information
• incentivize and facilitate sharing while
  restricting information flow

4
Electronic Markets Background

• Much work and attention focused on electronic
  futures markets as method of predicting future
  events
• proven effective for true/false and
  multiple-choice type predictions in places such
  as Iowa Electronic Markets and Hollywood Stock
  Exchange
• lack ability for more free-form type of
  predictions (where cannot enumerate the possible
  outcomes)
• information aggregation without sharing
• Electronic goods and services markets provide
  better model for information sharing
• examples eBay, monster.com and match.com
• ability to quickly identify complementary needs
  among a pool of thousands of potential buyers and
  sellers, to establish a market, and to easily
  perform any transactions
• easily auditable trail of transactions

5
Information Sharing Market Framework

• Participants buyers and sellers of information
  and data services
• sellers submit sealed bids plus sealed
  descriptions of information
• buyers submit sealed offers plus sealed
  descriptions of desired information
• Broker matches buyers and sellers
• if transaction realized, buyer receives copy of
  information from seller
• Large reward for piecing together pieces of
  information into coherent whole drives the market

6
Information Sharing Market Issues

• Advantages over bulletin board or open database
• incentivizes sharing rather than hoarding of
  information
• discourages wanton gathering of information
• Large number of issues, including
• security with participants having different
  privileges
• matchmaking how to accomplish without revealing
  too much, particularly about what information is
  being sold
• reputation discouraging sale of bad information
• economic (focus for this paper)
• what unit of payment? (e.g., fixed price vs.
  share of reward)
• price of a transaction?
• information about market to participants?
• information rights (does seller retain ability to
  sell again)?
• market dynamics?
• Investigate economic issues using a game that
  includes an information market

7
A Game Find the Ring

• Suspects R ring members among them
• Large reward for player that identifies the
  members of the ring
• Players each starting with M and C clues
• Clues partial information about which suspects
  in ring
• Equivalence (A and B either both in or both out)
• Anti-equivalence (either A or B in but not both)
• Negative (A not in ring)
• Play proceeds in rounds, with each round
  consisting of two phases
• players submit offers
• sell offers minimum price plus clue
• buy offers maximum price plus logical
  description of set of clues
• identification offers guess the ring
• broker resolves offers
• penalties (loss of money) for wrong
  identification
• reward for one (randomly chosen) correct id, and
  game over
• for each player, find best sell offer for one buy
  offer and split price
• for each player, find best buy offer for one sell
  offer and split price

8
Find the Ring (cont.)

• Stalemate if game proceeds N rounds without a
  transaction
• stalemate is a bad outcome, since ring not found
• Information available to all players
• number of suspects, size of ring, number of
  players, etc.
• summary of game state including leader board
  and number and average price of transactions last
  round
• Goals
• individual maximize money at end of game by
  collecting reward and/or by receiving more for
  selling clues than spent buying
• because reward not always given, not constant-sum
  game
• game maximize probability that ring found

9
Web Version Screenshot
10
Strategies and Agents

• Two main components of strategy (analyzed in
  detail in paper)
• which clues to try to buy
• important to know but specific to particular game
• pricing on buy and sell offers
• focus of economic analysis
• relevance to information markets in general
• Implemented software agents to play the game
• know which clues to buy
• optimal pricing strategy depends on what other
  players doing
• provide small number of parameters that allow
  different components (buying, selling, stalemate
  backoff) of pricing strategy to vary between
  agents

11
Experiments

• Experimental method
• select particular parameters for the game (number
  of players, number of suspects, size of ring,
  reward, starting money, number of initial clues
  of each type) and generate many different games
  from these parameters
• try different mixes of agent strategies until
  converge on equilibrium where no player/agent can
  improve by varying strategy
• measure properties of game/market, particularly
  fraction of time that ring found
• Vary parameters of game and see how this affects
  outcome

12
Results

• When sales competitive, prices low and market
  quickly proceeds to solution conversely, when
  lack of sales competition (information monopoly),
  prices high and tendency to get stuck in
  stalemate
• When players have sufficient money (relative to
  reward), even in competitive case likely to reach
  solution eventually however, when do not have
  sufficient money, tendency to get stuck in
  stalemate
• Change in broker mechanism will change specifics
  of the pricing strategies but will not change two
  basic conclusions above
• Conclusion for situation where non-competitive
  sales and reward-to-capital ratio is high, need
  some mechanism for breaking the deadlock, e.g.
  providing a way to split any future reward

13
Conclusions

• Information sharing market provides a potential
  mechanism for information sharing that
  incentivizes and facilitates cooperation while
  maintaining a restricted and regulated flow of
  information
• Find the Ring game provides mechanism for
  studying some of the properties of an information
  sharing market in a controlled setting
• Using software agents and Find the Ring, we
  performed experiments investigating these
  properties and discovered some conclusions that
  can help general design of information sharing
  markets
• Much work remains to be done before can implement
  real-world information sharing market