Minimum detectable effect size for main outcomes (accounting for sample
design and clustering)
We calculate the minimum detectable effect (MDE) to be 0.16 standard deviations with significance level of 0.05 and power of 0.8. Given that we have multiple treatment arms, we use Bonferroni correction and divide the level of significance by the number of experimental arms. Thus, with our new level of significance (0.0166), we can detect the proposed effect size if we have 1,650 sample size. To account the potential compliance problem and to have a sufficient sample size, we will increase the sample size by 10%, implying 1,815 sample size. Moreover, there could be another potential compliance problem from the control group who may apply for digital credit in other digital credit providers. We do not have data on this issue, nevertheless, will increase the sample size by another 10% to have sufficient sample size without the compliance group, implying a total sample size of 1,980. The sample size will be equally divided into treatment and control groups. In addition, evidence from administrative data shows that gender is an important factor for decision making in digital credit application and individual’s life outcomes. Hence, we stratify our sample using gender. Administrative data from COOP shows that 31% of digital credit borrowers were women. Using the gender composition of our target population, (31% female and 65% male), we propose a stratified randomization, implying a random sample of 614 female and 1366 males, totaling a sample size of 1,980 number of beneficiaries. Given the magnitude of treatment effects in the latest studies, we believe that this study is well powered for economically meaningful comparisons against control.