Experimental Design Details
1/ Pre-screening
Participants in the experiment need to be of either two identities. This pre-screening will be present at the beginning of each session for both the 'game' and the spectator setup and thus warrants its own explanation. I identify an individual as a Southerner (Northerner) if they meet the following criteria. First the individual was born in a Southern (Northern) region (Southern regions- London, South East, South West and East of England. Northern regions - North East, North West, Yorkshire and the Humber). Second the individual currently lives in a Southern (Northern) region. Third, the individual self-identifies with the corresponding identity.
The aim of this screening depends on the experiment session that is being run. In categorising individuals, I wish to identify if one has moved into or out of some region which would alter their exposure to other identities. Under the contact hyopthesis, this may affect one's trusting beliefs and pro-social behaviour. For instance, given that there is substantial net-South migration in England (ONS, 2023), Southerners will naturally have a higher exposure to Northerners than the contrary: a point I may exploit in a follow-up experiment.
In the 'game', I need to recruit at least 10 Northerners and 10 Southerners for each role. The remaining participants may be of any English origin. Therefore, I adopt a recruitment quota policy in the pre-screening.
In the spectator setting, the aim is to exclude individuals who do not identify as a Northerner or a Southerner. This is since these are my two identities of interest in the experiment.
Participants who do not meet the recruitment criteria in any stage are screened out of the study and paid a small compensation (£0.10) for their time. Participants who pass are moved on to the next stage of the experiment.
2/ The 'game'
The purpose of the game is not to measure or identify differences in trust beliefs or behaviour between identities but merely to provide real incentives for the spectator round. Participants are paid £1.00 as a base wage for participation and have the opportunity to earn up to £18.00 in bonus payment.
The game is split into two sub-experiments. Each experiment recruits 30 individuals. In the first sub-experiment, a recruitment quota system is used to ensure that there are at least 10 Northerners and 10 Southerners in the pool. All other participants may be of any English identity. The quota is implemented via the pre-screening feature. Participants are informed that they will play 2 games with another individual that is English. The players do not learn the identity of the person that they play these games with. In practice, I pair participants up across these two sub-experiments: I do not need these individuals to play simultaneously.
Players in the 'game' are told that in each game, they will be assigned a role of either person A or person B, with their partner playing the remaining role. They are informed that each token has a monetary value of £2.00 and that they will be paid their token balance in cash for one of the two games. They then proceed to play a trust game and a dictator game in a randomised order.
In the trust game they are given the following instructions: 'Person A starts with 3 tokens, and Person B starts with none. Person A can send some, all, or none of their tokens to Person B. Any tokens kept by Person A are theirs. For every token sent, Person B receives 3 tokens. For example, if Person A sends 2 tokens, Person B will get 6 tokens. Person B then decides how many tokens to return to Person A. Person A's earnings are the tokens they kept plus any returned to them. Person B's earnings are what they received minus what they returned.' In practice, players in the first sub-experiment are assigned the role of person B (the trustee) and players in the second sub-experiment are assigned the role of person A (the trustor).
The trustees are asked to state how many tokens they would like to return to person A for each possible amount that they could receive (0, 3, 6 or 9 tokens). This is a strategy method of elicitation. The trustees are told that their partner will make their decision also and this, together with their own decisions, will determine their payoff.
In the dictator game, players are given the following instructions: 'Person A first receives 5 tokens while person B receives nothing. Person A may send some, none, or all of their tokens to person B. Person A's earnings from this round are the tokens they do not send. Person B's earnings equal the tokens they receive.' In practice, players in the first sub-experiment are assigned the role of person A (the dictator) and players in the second experiment are assigned to the role of person B (the receiver). The dictators are asked to decide how many tokens they wish to send. The receivers do not make a decision in this stage.
Before each game, participants are required to pass a comprehension test before they proceed.
3/ The spectator
Spectators are recruited to guess the distribution of outcomes among 10 pairs who played the game. Spectators must also pass the pre-screening test. This way we can measure the trust of Northerners and Southerners separately. Spectators are paid £1.00 for their participation in the survey.
For each game, the spectators are given the same instructions as the players of the game and are then told that they must guess the frequency at which each possible decision was made among 10 trustees. Thus they are asked to elicit their beliefs of 3 distributions (one for each conditional transfer amount from the trustor) and are awarded £2.00 if they guess the exact frequency distribution for each question. After being given a chance to adjust their estimates, the spectators are then asked to guess the distribution of initial transfers in the trust game among 10 trustors.
The same procedure occurs for the dictator game where the spectators must state their beliefs about the distribution of transfers made by 10 dictators in the game. Spectators are awarded £2.00 if they guess the exact distribution.
As a final check, I ask spectators how much they agree with the following statement using a 7 point Likert scale. I then ask them to state their belief of how many of 100 individuals of a specific identity agree or strongly agree with this statement. The statement is 'Most people can be trusted'. Spectators are awarded £0.50 for each guess that is within 3 of the correct answer.
4/ Treatments
Before making any decisions, spectators are assigned to a treatment cell. I inform spectators that they will guess the distribution of outcomes among 10 decision makers. In the general treatment, I inform spectators that the decision makers are English and no further information is given. In the in-group treatment, I inform spectators that the decision makers are of the same identity as the spectators. In the out-group treatment, I inform spectators that the decision makers are of the other experimental identity to the spectators.
When I ask individuals how many of 100 individuals of some identity agree with the statement, I use other spectators to form this group of 100 and thus assign the identity that they observed in the other games to be the reference group.