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Using Classroom Experiments for Outreach Activities: a Public Goods Game Example


This case study relates to implementation of classroom experiments for taster sessions for local school students rather than current undergraduate students to highlight economics as a discipline rather than to teach a specific topic or idea. The classroom experiment discussed here is the public goods game initially discussed in Holt & Laury (1997). There were a number of changes made compared to when the activity is ran in the classroom. The main one being that I asked the students to work in pairs versus independently. There was a prize awarded for the team who made the most money. Recall the main trade-off of the game is whether to contribute to a common pool, which should others also, will yield a higher payoff than being purely selfish.

I will now go on to provide some context for the taster session before briefly discussing the main activity and finally closing with some remarks.


The participants in the taster session were boys in year 7 (ages 11-12) from schools in the region. The workshop was delivered twice with hear session having up to 15 students. The students were asked to work in pairs, which meant there was six groups of two and one group of three students. I asked them to sit separate from each other in order to minimise discussion between groups.

The session started with a short and relatively uninformative introduction, simply introducing myself and then immediately following a discussion around "what is economics?". They were allowed 2 minutes to discuss in partners before feeding back to the group. The responses were along the lines of “the world” or “business”; some students identified a link with Geography. The aim of this discussion was to get them thinking about what actually is economics and hopefully how this is related to the game they are going to play. Following this short introduction, I began to explain the game.


The main activity is a simplified public goods game modified from the format presented in Holt & Laury (1997). Here I will recap the game including any modifications that I made.

Student pairs were given an envelope, which contained the game instructions, their scorecard, four playing cards (two red and two black, the number on the cards does not matter) and a pen. I modified the initial instructions to include more steps and explanations for the students. This made them quite a bit longer. In addition to this, when talking through the instructions I also included an example scenario which went through how to fill in the scorecard. A possible addition might be to include this example on the physical copy of the scorecard they have so that they can easily refer to it whilst they learn the game.

Each round they needed to decide which two of their four cards to give me. If they decided to keep their red cards, they were worth £4 each to themselves. If they decided to contribute their red cards these were worth £1 to everyone. The black cards have no value and are purely to maintain anonymity during the game. Each round they took anonymous decisions and I collected and announced the number of red cards contributed and then gave each of their cards back to them for the next round.

Five rounds were played with the red cards being worth £4 if kept, then a further five rounds were played with the red cards being kept worth £2. After ten rounds, I allowed a short discussion for students to talk across teams. Followed by a final five rounds.

Students needed to record their decisions each round on a scorecard. This was then collected at the end of the game. The winner was announced and given the prize following the discussion of what was learned from the game. This delay in announcing the winner was to try to minimise the distraction during the discussion.

Given the age group, I added some structure to the discussion by presenting them with questions to think about. These included:

  • What do you think the game represented?
  • Did the change in the value of the red cards change your strategy?
  • Why did you decide to keep/give the red cards?
  • Why is this game important for economists?

Each question was discussed in turn, taking the opportunity to teach them what a public good is, and to think about how their behaviour influenced the provision of a public good. Students had their own motivations, mostly around being ‘selfish’ and wanting to win and make the most money. Moreover, they could not trust their classmates to also contribute; so did not want to lose money. These comments provided good discussion points to develop with the students.

Finally, I linked the game to three fields in economics, public, behavioural and experimental economics, explaining in turn what each field studies and how, linking back to the game that they just played for examples.

Concluding Remarks

Students enjoyed the game, were able to identify why they chose the strategies that they did, and what can be learned from playing the game. There were some challenges around the amount of time it took the students to fully understand the game. Whilst I included an example scenario, a better way might be to extend the first section to include a practice round which might allow students to fully understand the game before introducing the competitive element. Teachers and ambassadors are hugely helpful and influential, not just for behaviour management but working with the students to understand the game and to work in teams to work out their strategy.

Given the somewhat competitive nature of the activity, students were quite reactive to the announcement of the number of red cards I had collected. Particularly if they had contributed where others hadn’t. This meant that the game was not played always with total anonymity. Whilst this didn’t matter for the points that I wanted to discuss and for them to learn from the game, it did mean that the value of the discussion point following round ten was diminished. This is something to keep in mind if the activity is to be replicated. However, the extent to which this will be a problem in terms of maintaining anonymity and creating valid discussion will vary with the age group.


Holt, Charles A., and Susan K. Laury. 1997. "Classroom Games: Voluntary Provision of a Public Good." Journal of Economic Perspectives, 11 (4): 209-215.

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