21 is a very simple game. 21 cards lay face-down on the table, and 2 players take turns choosing to remove either 1, 2, or 3 cards from the table. Whoever takes the last card from the table wins.
When first playing 21, it is not clear how early decisions (should I remove 1, 2, or 3 cards on my first turn?) impact the outcome. As hard as you try to logic out the first move, most students are not going to get it. Have them play the game, however, and 10 minutes later all of them have cracked the solution, are excited about what they just accomplished, and ready to learn about recursive logic in finite games with full information. If you don’t believe me, play the game yourselves a few times (and watch Survivor’s dramatic version).
While I taught this case while teaching a class specifically on game theory, I learned that games can be used to teach many concepts in public policy and microeconomics and have several unique advantages.
First, they get students involved. Students go from having passive consumption of market failures to active engagement with the problems.
Second, they force students to think from the perspectives of everyone involved in the exercise. I find that public policy students (and indeed most people with opinions on policy) start with ideas that a problem facing society would be simple to solve, and attribute a lack of action as evidence of political apathy, corruption, or bad-faith from the opposing party. As students see past the surface and engage with the complexities of a policy dilemma, they are able to think more critically about how to balance multiple goals to find policy compromises.
Third, policy is full of instances where imperfect markets lend themselves to ‘gaming the system’, leading to market failures. Whether it is over-consuming a common pool resource, acting as a monopolist, or cheating on regulations, market-failures impose harms on others based on strategic actions. Much of public policy is trying to change the rules to prevent anti-social behavior and promote market-based competition that is in the interest of everyone.
A simple example comes from a ‘tragedy of the commons’ type example. All my students were fishermen, and could choose how many fish to draw from a lake. Take to many, and in the next round there would be fewer to draw from. The game lasted between 3 and 6 rounds, and there was a possibility that the fish-stock could be completely depleted by the end of round 3. To make things interesting, students earned small percentages of extra-credit on an upcoming test (students ended up earning between .7 and 2.2% of extra credit). Answers were submitted by a doodle poll that allowed me to immediately graph and anonymously display results for each round.
The point of the game is that everyone has an incentive to overfish for immediate profits, but that to get the most amount of extra credit the fishery needs to be sustained. The eight students rose to the occasion. The first-round answers had a wide range, but as the game progressed they started talking to each other. Rather than urging everyone to take close to zero, they set an allotment for how many fish to take so that the fishery would still expand to the next round. They discussed how they’d be able to take more fish next time when fish were more plentiful. And though some took more than the class target, the fishery still expanded.
There was significant pride in both having figured out what the game was trying to do, having overcome the trust barriers, and excitement for extra credit won. Following, we had a vibrant discussion on Dr. Elinor Ostrom’s work on common-pool resources. Students responded to questions by imagining tweaks to the game they had just played and thinking through how slight rules variations could have impacted the outcome. What if they knew there would be infinite rounds? What if they could see who had taken the most fish?
I have yet to try games with a larger class size, and my attempt to run a game over zoom had only moderate success (though it was hard to tell how engaged students were in breakout rooms). I have learned to prioritize simplicity in designing games. I also have learned to create games where there is no ‘right answer’, and where multiple strategies can work. Most importantly, I have learned that the most learning happens when students have the opportunity to share their strategies, explain their actions, and let other students see their thought process, motivations, and assumptions about the behaviors of their classmates.