My Intro to IR Class is full of Realists

Last Tuesday in POLI 1140, the students completed an class oil-market exercise in which pairs of students engaged in a strategic situation that required them to sell oil at specific prices. Many students were able to understand relatively quickly that the “Oil Game” was an example of the classic prisoner’s dilemma (PD). As Mingst and Arreguin-Toft note on page 78, the crucial point about the prisoner’s dilemma:

Neither prisoner knows how the other will respond; the cost of not confessing if the other confesses is extraordinarily high. So both will confess, leading to a less-than-optimal outcome for both.

From a theoretical perspective (and empirical tests have generally confirmed this) there will likely be very little cooperation in one-shot prisoner’s dilemma-type situations. Over repeated interaction, however, learning can contribute to higher levels of cooperation. With respect to IR theories, specifically, it is argued that realists are more likely to defect in PD situations as they are concerned with relative gains. Liberals, on the other hand, who value absolute gains more highly, are more likely to cooperate and create socially more optimal outcomes. What were the results in our class?

The graph above plots the level of cooperation across all six years (stages) of the exercise. There were seven groups and what the probabilities demonstrate is that in each year there was only one group for which the interaction was cooperative. In year 2, there was not a single instance of cooperation. Moreover, it was the same group that cooperated. Therefore, one of the groups cooperated 5 out of 6 years, while none of the other six groups cooperated a single time over the course of the sex years!! What a bunch of realists!!

If you were involved in this exercise, please let me know your reactions to what happened.

Playing the Dominant Strategy in a Prisoner’s Dilemma Situation

As you’ll see in lecture tomorrow, instrumentally rational players will also choose to “defect” in a priosoner’s dilemma type situation even though they could be much better off absolutely if they and their opponents could learn to cooperate.  The chart below has been created using data from the simulation of yesterday.  What is take-home message from the chart?  Why is the relationship between the phenomena displayed not completely linear?  Think about the nature (i.e., the specific rules) of the oil game we played yesterday. (The plot below is a box plot, which is a way of summarizing the means, range, and certain percentiles of the values of a single variable based on another variable.)


Results from a Prisoner’s Dilemma Simulation–The Oil Game

Today in class, you competed in groups to maximize total profits in a simulation called “the Oil Game.” You represented one of two competing oil producers–Iraz and Sabia–trying to maximize profits selling oil to a net importer of oil–ESYUVI (the names were created using a random letter-generator–I swear!). Most of you recognized very quickly, if not immediately, that the simulation was a modified Prisoner’s Dilemma situation. As I’ll discuss on Friday, in a Prisoner’s Dilemma situation, players acting in an instrumentally rational manner will always choose not to cooperate (i.e., “defect”), because it is a dominant strategy. What makes the situation a dilemma is that the players could do much better were they able to cooperate and trust one another.


The compelling logic of the prisoner’s dilemma, along with some strong empirical evidence, is used by realists to support their arguments regarding the nature of interaction in the international world. Liberals, on the other hand, argue that there is much more cooperation in the world than realists would predict. Thus, despite the structure of the prisoner’s dilemma, players are able to cooperate in international politics. What factors do you think make cooperation more likely? Less likely? Why?

The results from our simulation today are in graphical form above. You’ll note that communication was not allowed for Years 1, 2, and 4; communication was allowed for Year 3, and communication (to decide what to do for Years 5 and 6) was allowed prior to Year 5. The results from this class are consistent with the expectations. I would note the relatively low level of cooperation throughout, rising only initially after the first episode of communication.