Minimum detectable effect size for main outcomes (accounting for sample
design and clustering)
The list of Treatment villages are:
North Yamar irrigation site (Pale and Yinmarbin townships):
Village tract Village
Kyay Nin Nar Daw Mauk
Kyae Tha Hmyar Kyay Tha Myar East
Kyae Tha Hmyar Khin Ma = min ma anauk
Poke Par Poke Par
Mon Kyaing Mon Kyaing
Kan Gyi Ale Thi Tinn
Min Kan Gyi Min Kan Gyi
Min Kan Gyi Min Kan Tike
Lel Ngauk Lel Ngauk
Sinthe (Tatkone township):
Village tract Village
Kyaung Kaing Aung Thar
Kyaung Kaing Yway Su
Oke Shit Kone Oke Shit Kone
Kyay Chaung HTa Yan Kar
Ma Gyi Pin Pyaw
Ma Gyi Pin Yae Twin Phyu
Minimum sample size:
We used clustersampsi in Stata to compute for the minimum number of clusters needed and the number of sample per cluster. For dietary diversity score, the mean is 4.70, and standard deviation is 1.32 among surveyed respondents in the baseline survey. Using complete randomization, minimum sample size per treatment arm would have been 111 with 80% power and 5% level of significance. Given the randomization done at village level, the sample size has to be inflated for intraclass correlation (ICC), which is 1.92. With this design effect inflator, the sample size of 270 respondents in 9 villages in each treatment arm can detect a minimum of 0.5 increase in the dietary score. Some nutrition BCC projects were able to achieve this impact, and discussions with nutrition experts in Myanmar indicate that this target is feasible.
For women’ empowerment score, the mean is 0.61 and the standard deviation is 0.13 among surveyed female respondents in the baseline survey. Using complete randomization, minimum sample size per treatment arm would have been 75 with 80% power and 5% level of significance. Given the randomization done at village level, the sample size has to be inflated for intraclass correlation (ICC), which is 3.06. With this design effect inflator, the sample size of 270 respondents in 9 villages in each treatment arm can detect a minimum of 10% increase in the empowerment score to 0.67. Preliminary analysis of the ANGeL project in Bangladesh show this impact is achieved in the context of that project (Quisumbing et al 2019). This is feasible in our study site, with 37% of the villages achieving this at baseline.
For women being empowered (dummy), the mean is 0.21 and the standard deviation is 0.41 among surveyed households in the baseline survey. Using complete randomization, minimum sample size per treatment arm would have been 207 with 80% power and 5% level of significance. Given the randomization done at village level, the sample size has to be inflated for intraclass correlation (ICC), which is 1.89. With this design effect inflator, the sample size of 420 respondents in 14 villages in each treatment arm can detect a minimum of 27% increase in the proportion of households achieving parity to 0.43. Preliminary analysis of the ANGeL project in Bangladesh show this impact is achieved in the context of that project (Quisumbing et al 2019). This is feasible in our study site, with 43% of the villages achieving this level at baseline.
For intrahousehold inequality score, the mean is 0.12 and the standard deviation is 0.17 among surveyed households in the baseline survey. Using complete randomization, minimum sample size per treatment arm would have been 127 with 80% power and 5% level of significance. Given the randomization done at village level, the sample size has to be inflated for intraclass correlation (ICC), which is 1.89. With this design effect inflator, the sample size of 270 respondents in 9 villages in each treatment arm can detect a minimum of 50% decrease in the intrahousehold inequality score to 0.06. This is feasible in our study site, with 10% of the villages achieving this level at baseline.
For gender parity, the mean is 0.33 and the standard deviation is 0.48 among surveyed households in the baseline survey. Using complete randomization, minimum sample size per treatment arm would have been 288 with 80% power and 5% level of significance. Given the randomization done at village level, the sample size has to be inflated for intraclass correlation (ICC), which is 1.40. With this design effect inflator, the sample size of 450 respondents in 15 villages in each treatment arm can detect a minimum of 33% increase in the proportion of households achieving parity to 0.45. This level is achieved in 20% of the villages in the study site at baseline.
The baseline survey covers 30 villages, 29-32 households randomly selected per village.