After the experiment is over, participants are paid. There are two major types of payment: fixed payments or a combination of fixed and variable payments. The fixed payment is a lump sum the experimenter pays equally to all participants. If a combination of fixed and variable payments is used, a participant receives a fixed payment of £3 as show-up fee and will earn a variable payment depending on the participant’s decisions and those of other participants. The average for both types of payment is £10 per hour. This applies to all experiments conducted in the laboratory so that no competition amongst experiments occurs. In order to receive their payment, participants must sign a receipt form for accounting purposes.