Networks, Coordination and Cooperation

1. Networks, Coordination and Cooperation • Nicholas Weller • USC Department of Political Science and School of International Relations • Collaborators: • Daniel Enemark, USC Law School • Mathew McCubbins, USC Marshall, Law and Political Science • Mohan Paturi, UCSD Computer Science

2. Central questions • How does network structure affect a group of people’s ability to solve collective action problems? • What aspects of structure affect collective action? • Answers can help us to understand the conditions when collective action problems can be solved and how institutions can aid/impede solutions

3. Collective action requires coordination • Research about collective action focuses on cooperation. But, coordination is still needed. • “Because every ongoing social process possesses a multiplicity of equilibria, opportunities to cooperate and the concomitant problem of coordinating to one of these equilibria are omnipresent (Niou and Ordeshook 1994, p. 210).” • Implicitly, the focus on cooperation assumed that coordination was easy (or easier) • “Multiple equilibria are a major obstacle to cooperation that was downplayed by the early emphasis on 2X2 games.” (Koremenos et al. 2001)

4. Role of communication • In settings where coordination is important each individual’s best course of action depends on assessment of others’ likely action. • What affects this assessment? • “Secure and cheap tools of communication lower transaction costs for the organization of collective action, with social media in particular allowing like-minded members to find one another and to make their true beliefs known in a semi-public setting.” (Lynch 2011) • “Before Egypt shut off the Internet and mobile phones, before it even started blocking Twitter and Facebook, those tools were used to coordinate and spread the word about the demonstrations that were scheduled for January 25. Without these mass organizing tools, it’s likely that fewer people would have known about the protests, or summoned the kind of courage that’s made possible by knowing you’re not the only one sticking your neck out.” http://www.fastcompany.com/1722492/how-social-media-accelerated-the-uprising-in-egypt • Solidarity leaders in Poland transmitted information via foreign radio networks with details about their strike activities, which would then be broadcast in news reports throughout the country (Chong 1993, p. 135) • Communication seems important, but how?

5. Network as Communication Structure • Network can be used to model communication between actors; can represent arbitrary structure of communication • Nodes: actors in a network • Edges: presence of communication • Why use a network? • Allows modeling of arbitrary structure of communication

6. Possible Networks with 4 actors Everyone hears everyone

7. Coordination on a Network • Communication: embed subjects in a network • Node == actor • Edge == communication and constraint • Coordination: multiple solutions to each task • Cooperation: some players will have to accept less earnings for group to solve a problem • Asymmetric benefits to coordination • Costs to take an action

8. Experimental Basics • Task: Color the nodes of a network • Color nodes differently than neighbors graph coloring • Color nodes same as neighbors consensus • There are multiple outcomes that satisfy the condition for a proper coloring. • Global solution as a result of local actions • Task is easy to explain good for experiments

9. Experimental Basics, II • 16 subjects • 3 minutes to solve problem • $1 baseline payment iff successful • Colors change for each session and differ for subjects • Decisions are asynchronous and instantly known • Within group design

10. Subject Information Subjects know: Number of local neighbors Number of edges for each neighbor Color of neighbors Time elapsed in session Whether a network is colored correctly How and what they get paid Subjects DON’T know Structure of entire network Who their local neighbors are

13. Symmetric vs. Asymmetric Coordination McCubbins, Paturi and Weller. 2009. “Connected Coordination: Network Structure and Group Coordination.”American Politics Research

14. Symmetric vs Asymmetric • Symmetric (pure) coordination: subjects each receive the same amount for a solution • Asymmetric (impure, battle of sexes): for the group to solve the problem ½ of the subjects must receive the lower of two payoffs • Baseline payoff is $1 • Bonus payoff ranges from $1 to $4

15. Expectations for Symmetric and Asymmetric Coordination Greater number of edges within networks will lead to faster solutions Greater number of edges will also reduce impact of asymmetric coordination

19. Time, Connectivity, and Asymmetry

21. Costly coordination • If there is a cost to take an action to achieve coordination, then the task involves both cooperation and coordination. • Every player would rather have others pay the cost to achieve coordination, but all are better off if coordination occurs (similar to Stag Hunt or Assurance Game) • Two key decisions in this game: • Initial move: only pay the cost to move if probability of successful completion is sufficiently high • Subsequent moves: if initial moves do not lead to coordination. Do players pay to move again?

22. Experiment Overview • Subjects Know • 16 subjects in each network • Cost to choose color (0, 5, 10, 20, 30, 50) • Within and between group design • All groups had multiple treatment conditions, order varied • 3 minutes to coordinate • $1 iff successful, $0 if not; costs for taking an action deducted from the $1 or $0 • Number of neighbors and their degree; color of the neighbor at any moment • Subjects quizzed on all of this to ensure compliance • Subjects Don’t Know • Anything beyond their local neighborhood • Who the local neighbors are; they change randomly for each trial • Progress of the global coordination task

23. Expectations • Costs will slow coordination • increases in cost will further slow coordination • Costs increase the time to the first move because players are waiting to see if someone else will incur the initial cost and attempt to lead the group to a solution (i.e. Strategic Delay, Choi et al. 2008, Chong 1991 idea of delay in assurance game) • Costs increase efficiency (i.e. players take fewer actions to achieve coordination. • Networks with more edges will be solved faster than networks with fewer edges, c.p. • Networks with higher degree variance will be solved more quickly, c.p.

25. Costs slow coordination

26. Effect of Increasing Costs on Coordination

27. Costs cause delay in time to first move

28. Costs reduce number of moves

29. More edges = faster solutions 24 edges 56 edges

30. “Leaders” = faster coordination 24 edges 0 degree variance 15 edges 11.5 degree variance

31. Conclusion • Collective political action requires both coordination and cooperation • Communication is crucial to solving these types of problems • Communication structure (network) mediates effects of costs and asymmetry • Communication structure affects coordination via multiple paths • Amount of information (number of edges), BUT adding edges can also make problem more difficult • Presence of leaders (degree variance)

32. Looked at two common modifications to pure coordination games – asymmetric preferences and costs to take an action.