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Registration

Field Before After
Trial Status in_development on_going
Trial End Date May 31, 2022 December 31, 2023
Last Published March 31, 2022 03:32 PM June 14, 2023 02:06 AM
Study Withdrawn No
Intervention Completion Date May 25, 2022
Data Collection Complete Yes
Final Sample Size: Number of Clusters (Unit of Randomization) 205 subjects.
Was attrition correlated with treatment status? No
Final Sample Size: Total Number of Observations 1025 rounds of real-effort tasks.
Final Sample Size (or Number of Clusters) by Treatment Arms 75 subjects in UBI, 75 subjects in NIT, 55 subjects in the benchmark treatments.
Data Collection Completion Date May 25, 2022
Intervention (Public) This is a laboratory experiment employing a between-subject design. In each session with ten participants, subjects are randomly allocated into two groups of five using the experimental software zTree. This matching remains fixed throughout the experiment. They play a real-effort game five times. In each game, they have 4 minutes to complete tasks and those with higher performance receive higher rewards. The real-effort task is to type a randomly generated block of 20 characters backward into a text box. The blocks of characters were randomly drawn with replacement from a pool of 500 pre-generated blocks. After submitting the text, participants receive feedback and a new block of characters. They may complete as many tasks as they wished. At the end of the period, participants learned the number of correctly typed blocks. Each completed task is rewarded with 0.30 SGD gross payment. In the control group (BM), there is no tax and no transfer. Participants always receive the full flat-rate payment for each completed task. The repeated game is played in two conditions that are identical in the distribution of final payoffs but different in how redistribution is framed. In the negative income tax (NIT) treatment, all tax is born by subjects that earn above the mean income. In particular, the tax is equivalent to half of the difference between the gross income of the subject and the average gross income. Those below average receive a negative tax: they don't pay tax, only receive it. The transfer is equal to half of the difference between their income and the average. By design, the sum of taxes equals the sum of transfers. In the universal basic income (UBI) treatment, all subjects pay 50\% of their gross income as tax. Then, they receive an unconditional payment after each round that is an equal share of all tax revenues. The list of net incomes is identical to that of the NIT treatment for any gross income levels in the group. This is a laboratory experiment employing a between-subject design. In each session with ten participants, subjects are randomly allocated into two groups of five using the experimental software zTree. This matching remains fixed throughout the experiment. They play a real-effort game five times. In each game, they have 4 minutes to complete tasks and those with higher performance receive higher rewards. The real-effort task is to type a randomly generated block of 20 characters backward into a text box. The blocks of characters were randomly drawn with replacement from a pool of 500 pre-generated blocks. After submitting the text, participants receive feedback and a new block of characters. They may complete as many tasks as they wished. At the end of the period, participants learned the number of correctly typed blocks. Each completed task is rewarded with 0.30 SGD gross payment. In the control group (BM), there is no tax and no transfer. Participants always receive the full flat-rate payment for each completed task. The repeated game is played in two conditions that are identical in the distribution of final payoffs but different in how redistribution is framed. In the negative income tax (NIT) treatment, all tax is born by subjects that earn above the mean income. In particular, the tax is equivalent to 30% or 50% (depending on the treatment) of the difference between the gross income of the subject and the average gross income. Those below average receive a negative tax: they don't pay tax, only receive it. The transfer is equal to 30% or 50% (depending on the treatment) of the difference between their income and the average. By design, the sum of taxes equals the sum of transfers. In the universal basic income (UBI) treatment, all subjects pay 30% or 50% (depending on the treatment) of their gross income as tax. Then, they receive an unconditional payment after each round that is an equal share of all tax revenues. The list of net incomes is identical to that of the NIT treatment for any gross income levels in the group.
Intervention End Date May 31, 2022 December 31, 2023
Planned Number of Clusters 13 sessions. 30 sessions.
Planned Number of Observations 195 subjects, 975 observations. 305 subjects, 1525 observations.
Sample size (or number of clusters) by treatment arms 75 subjects in UBI 75 subjects in NIT 45 subjects in BM 75 subjects in UBI 50% tax 75 subjects in NIT 50% tax 55 subjects in BM 50 subjects in NIT 30% tax 50 subjects in UBI 30% tax
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