**Table 5: Power of Studies to Detect Increases in Profits or Sales**

||||||||<br>**Power to D**|<br>**etect Increase**|<br>**of:**|
|---|---|---|---|---|---|---|---|---|---|
|**Study**|**Group or Individual **<br>**Randomization?**|**Sample Sizes in Treatment (T)**<br>**and Control(C) Groups**|**C.V.**<br>**Profits**|**C.V.**<br>**Revenues**|**Attendance**<br>**Rate**|**25% in**<br>**Profits**|**50% in**<br>**Profits**|**25% in**<br>**Revenues**|**50% in**<br>**Revenues**|
|Berge et al. (2012)|Group|119 (T), 116 (C) groups (a)|0.80|1.47|83%|0.631-0.842|0.996-1.000|0.239-0.365|0.705-0.897|
|Bruhn and Zia (2012)|Individual|297 (T), 148 (C)|2.69|n.a.|39%|0.070|0.132|n.a.|n.a.|
|Calderon et al. (2012)|Two-stage|164 (T), 711 (C) (c)|1.51|1.53|65%|0.263 (b)|0.754 (b)|0.257 (b)|0.743 (b)|
|De Mel et al. (2012)|Individual|200 (T1), 200 (T2), 228 (C)|0.49|0.91|70%|0.990|1.000|0.632|0.994|
|Drexler et al. (2012)|Individual|402 (T1), 404 (T2), 387 (C)|n.a.|1.63|49%|n.a.|n.a.|0.231|0.686|
|Giné and Mansuri (2011)|Group|373 (T), 374 (C) groups|n.a.|n.a.|50%|n.a.|n.a.|n.a.|n.a.|
|Glaub et al. (2012)|Individual|56 (T), 53 (C)|n.a.|n.a.|84%|n.a.|n.a.|n.a.|n.a.|
|Karlan and Valdivia (2011)|Group|138 (T), 101 (C) groups|-24.96|2.30|80%|0.057 (b)|0.078 (b)|0.120-0.757|0.335-1.000|
|Klinger and Schündeln (2011)|Individual RD|377 (T), 278 (C)|n.a.|2.51|n.a.|n.a.|n.a.|0.259 (d)|0.746 (d)|
|Mano et al. (2012)|Individual|47 (T), 66 (C) (b)|1.23|1.20|87%|0.188|0.571|0.195|0.592|
|Sonobe et al. (2011)||||||||||
|Tanzania|Individual|53 (T), 59 (C)|1.99|1.61|92%|0.109|0.292|0.141|0.414|
|Ethiopia|Individual|56 (T), 47 (C)|1.94|2.49|75%|0.087|0.204|0.072|0.142|
|Vietnam - Steel|Individual|110 (T), 70 (C)|1.59|0.93|39%|0.075|0.153|0.124|0.353|
|Vietnam - Knitwear|Individual|91 (T), 70 (C)|-8.15|2.34|59%|0.052|0.058|0.074|0.150|
|Valdivia(2012)|Individual|709(T1),709(T2),565(C)|n.a.|2.29|51%|n.a.|n.a.|0.207|0.626|

Notes: n.a. denotes not available, either because the study did not report this outcome, or because it didn't report the coefficient of variation (C.V.). Personal correspondence with authors used to obtain C.V.s from studies which only report sample means and not standard deviations. Where range is shown, first number is power if intra-cluster correlation is one, second is power if intra-cluster correlation is zero.

(a) Numbers in control and training only groups - the study also includes groups with grants. Power calculations based on random assignment to groups, which is the working assumption of the paper, although in practice true random assignment only occurred at the branch-day of the week level, in which case power is zero. (b) Power calculation assuming randomization was at the individual level. Actual power will be lower once group-level randomization is accounted for. (c) Assignment first at the village level to 7 treated villages and 10 control villages, then assignment within village to treatment and control. (d) Study does not examine revenue as an outcome, since some data is collected retrospectively.

Power calculations ignore survey attrition, which would further lower power. They also assume entire sample are existing enterprises. Attendance rate for Klinger and Schündeln (2011) assumed to be 90% for purpose of power calculations.

Power calculations assume one baseline and one post-treatment survey, with an autocorrelation in the outcome variable of 0.5, and ANCOVA estimation.

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