Coordination And Cooperation

### Problems

Q197. Explain and give an example of a dominant strategy in a prisoner's dilemma game.

Q251. Suppose the (time) cost of waiting behind someone with a big shopping cart in the super market checkout line is 10 minutes while the time behind someone with a very few items is 2 minutes. Consider three cities, A, B, and C. Suppose the probability of running into someone again soon in the grocery store is 0.1, 0.2, and 0.4 in cities A, B, and C, respectively. What do we predict? Which "path to cooperation" does this illustrate?

Q252. Consider this network in which green agents are cooperators and violet are defectors and the cost of cooperating is 2 while the benefit of being cooperated with is 5. Where is the equilibrium is people's behavior changes based on their network experiences?

Q253. Consider this network in which green agents are cooperators and violet are defectors and the cost of cooperating is 2 while the benefit of being cooperated with is 5. Where is the equilibrium is people's behavior changes based on their network experiences?

Q254. Just based on reasoning, explain the relation among relatedness, cost of cooperation, and benefit of cooperation in kin selection as a mechanism for achieving cooperation in the face of prisoner's dilemma scenarios.

Q255. Work through the section on direct reciprocity in Nowak and Sigmund, "How Populations Cohere."

Q256. Consider the collective action model described in Lecture 17.4: Collective Action and Common Pool Resource Problems where $x_j$ is the cost to me to "pitch in" and do my part in some collective effort. Each member of the collective reaps benefits from the contributions of those who decide to pitch in. In particular, they receive some fraction $\beta$ of all the contributions. Their net benefit is thus, this amount minus the effort they contribute. In other words,

(1)
\begin{align} Payoff_j = -x_j + \beta \sum x_i \end{align}

Suppose you are in a class of 21 students and everyone is expected to prepare for class in a manner that costs 1 unit of life. In the class itself, things go much better when people are prepared and we estimate that the benefit a student derives from the class is equal to 0.2 units of life for each person who comes prepared.

(a) What is your net payoff if you do the reading half the class rest of the class comes prepared too?
(b) What is the benefit to a shirker under the same conditions?
(c) How many people do you need to think are going to do the reading to make it worth it to do the reading?

Q257. (a) Explain the equations for common pool resource problems as discussed in Lecture 17.4: "Collective Action and Common Pool Resource Problems":

$x_j$ : amount consumed by person j

$X$ : total consumed

Amount available next period: $C_{T+1} = (C_T - X)^2$

(b) Propose values of these variables that would result in a steady state equilibrium value of the resource.

Q258. Insofar as particulars matter, what's the difference between cows, lobsters, and whether you live up stream or downstream?

Q259. What are the 5+2 means of achieving cooperation in the face of structural arrangements that "mandate" non-cooperation in human relationships?

Q260. Explain how "group selection" can give rise to cooperative behavior in human society.

### Collective Action, Prisoners Dilemma, and the Commons

BEFORE Class

Start this section with the short introduction video (17.1) and then read the brief entry in the Stanford Encyclopedia and view lecture 17.2.

Read Nowak and Sigmund on cooperation and then view lecture 17.3.

1. SEP Lecture 17.1: The Prisoners' Dilemma and Collective Action (3:44)
2. SEP Lecture 17.2: The Prisoners' Dilemma Game (13:45)
3. SEP Lecture The Prisoners' Dilemma in the Stanford Encyclopedia of Philosophy
4. SEP Lecture 17.3: Seven Ways To Cooperation (15:20)
1. SEP Lecture 17.4: Collective Action and Common Pool Resource Problems (7:23)
2. Read Ostrom: "Going Beyond Panaceas"
3. SEP Lecture 17.5: No Panacea (6:03)

### Cooperation

1. Repetition
2. Reputation
3. Network
4. Group Selection (frequency of group conflict)
5. Kin Selection
1. r > c/b
6. Laws and Prohibitions
7. Incentives