An initial pool of subjects is asked to refer members of their social networks to participate in the experiment in subsequent rounds. We go door to door to recruit initial participants. These households are offered a fixed wage if they send an adult male household member to the study site, which is located nearby. Participants are assigned an appointment time, requested to be available for two hours of work, and are provided with a single coupon to ensure that only one male per household attends. Upon arrival at the study site, individuals complete a survey that includes questions on demographics, labor force participation, social networks, and two measures of cognitive ability: the digit span test and raven’s matrices. This initial group (original participants or OPs) faces an experimental treatment randomized along several dimensions. OPs are asked to complete one (randomly chosen) task: one task emphasizes cognitive ability while a second task emphasizes pure effort. The majority of our sample (including all high-stakes treatment groups) was assigned to the cognitive task, which we focus on in the published paper.
In the cognitive test, participants were asked to arrange a group of colored swatches according to a set of logical rules. A supervisor explains the rules to each participant, who is given a maximum time limit to complete each puzzle. When the participant believes he has solved a puzzle, he signals the supervisor, who either lets the participant continue to the next puzzle if the solution is correct, or points out the error and tells the participant to try again, allowing up to three incorrect attempts per puzzle.
At the end of the experiment, individuals are paid Rs 135 for their participation. They are also offered payment to return with a male friend or family member (a referral) between the ages of 18 and 60. All OPs are specifically asked to return with a referral “who would be good at the task you just completed.” A second randomization occurs to determine the amount of payment the OP will receive when he returns with a referral. Payment varies along two dimensions: the amount of pay and whether pay may depend on the referral’s performance. Participants are ensured that their payment will be at least a minimal threshold and given the specific terms of the payment arrangement. OPs are informed of the offer payment immediately prior to their exit from the laboratory. All participants are asked to make an appointment to return with a referral in a designated three-day window.