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Fields Changed

Registration

Field Before After
Trial End Date October 31, 2023 October 31, 2025
Last Published November 07, 2022 04:31 PM March 31, 2025 08:09 AM
Intervention End Date October 31, 2023 October 31, 2025
Planned Number of Observations We will recruit as many participants as we can, up to our budgeted limit of 200 . Note half will be potential donors and half potential charity recipients. We will recruit as many participants as we can, up to our budgeted limit of 200 . Note half will be potential donors and half potential charity recipients. Modification 01 - We recruited N = 165 (i.e., we did not reach our goal of N = 200). The modification is to attempt to recruit an additional N = 188. See the attached "rcb-Pre-reg004B-v01a-AEA-RCT-Registry-Modification01.pdf"
Sample size (or number of clusters) by treatment arms 100 participants internal; 100 participants external. 100 participants internal; 100 participants external. Modification 01 - 176 participants internal; 176 participants external.
Power calculation: Minimum Detectable Effect Size for Main Outcomes An effect size of .20 to .25 in the difference between the proportions of Low-internal vs. Low-external who ask for charity. See the attached power analysis. An effect size of .20 to .25 in the difference between the proportions of Low-internal vs. Low-external who ask for charity. See the attached power analysis. Modification 01 - 80% power to detect: (1) A difference of -16.75 in the take-up rate of charity. (2a) A difference of -18.5 in the donation rate to charity. (2b) A difference of $1.37 in the average amount donated to charity. See the attached “rcb-Pre-reg003B-v01a-PowerAnalysis-Modification01.pdf”
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