Experimental Design Details
The experiment is a computerized laboratory experiment implemented in z-Tree (Fischbacher, 2007). Each session involves a variable number of participants (typically between 16 and 24, depending on attendance), who are randomly assigned to the role of "employer" (principal) or "worker" (agent). Roles are fixed for the duration of the experiment. The experiment consists of 20 rounds, with random rematching of principal-agent pairs in each round (stranger matching).
Task structure. Each round consists of two stages. In each stage, the agent chooses an effort level (integer from 0 to 10), which costs c(e) = 0.25e². The outcome of each stage (low, medium, or high performance) is determined stochastically by the agent's effort and task difficulty. Task difficulty is either easy (θ = 2/5, probability 1/2) or difficult (θ = 1/10, probability 1/2), drawn at the start of each round and constant across both stages. Neither party is told the task difficulty. The exact outcome probabilities are implemented in the z-Tree program.
Payoffs from outcomes are as follows: low performance yields 0 for the worker and 0 for the employer; medium performance yields 40 for the worker and 20 for the employer; high performance yields 100 for the worker and 120 for the employer.
After stage 1, the principal observes the outcome and may send a message. If the outcome is high, the principal can send "Well Done" or no message. If the outcome is low, the principal can send "Not Good Enough" or no message. If the outcome is medium, no message can be sent. After receiving any message or no message, the agent chooses effort for stage 2. At the end of each round, both parties learn the outcomes of both stages.
Session procedures. We aim to recruit approximately 35–50 principals (70–100 participants in total), distributed across four to six sessions of variable size depending on attendance. Each session lasts approximately 40 minutes. At the beginning of each session, participants receive written instructions, which are also read aloud by the experimenter. Participants have an opportunity to ask questions privately. A practice round is conducted before the main experiment begins.
All subjects receive a guaranteed show-up fee of 550 ECU, plus performance-based earnings. At the end of each session, earnings are determined by a random selection of 4 out of 20 rounds. The exchange rate is 1 ECU = 1 RUB (Russian rubles). Expected earnings are approximately 900 RUB per participant for a 40-minute session.
After the experiment, subjects complete a short questionnaire collecting age, gender, field of study/major, optional GPA or GPA range, and questions about feedback strategies and attitudes toward positive and negative feedback. Principals are additionally asked about their perception of the effectiveness of their feedback.