Eighty percent of those assigned to training started at least one session, and 61 percent completed all sessions to graduate. This demonstrates the feasibility of scaling to thousands over a wide geographic range. However, we found three factors limit the ability to scale to tens or hundreds of thousands. First, the conversion rate from advertising and approaching entrepreneurs through partners was low, and it required multiple rounds of recruitment to obtain our sample. Second, while the businesses recruited are small and have household incomes much lower than the Mexican average, the women who self-select into training are younger, more educated, and are more likely to have an employee than the average Mexican microenterprise, suggesting limits on reaching the poorest and least educated. Finally, the cost savings from switching from in-person to online training are not that large ($50 versus $62 per participant), reflecting that the main costs of instructor time, recruitment, and material development are similar for on- and offline synchronous training.<sup>1</sup> Remote training via Zoom does improve business practices and business performance in the period immediately after training, but these impacts do not last. We conducted follow-up surveys approximately 2 and 6 months post-training. After two months, women assigned to our Zoom training treatment have significantly improved their business practices by 5.4 percentage points. Monthly sales are 4100 pesos ($240) higher, which is statistically significant and a 24 percent increase on the control mean, while monthly profits are a statistically insignificant 648 pesos ($38) higher, or 10% of the control mean. The 6-month impacts are all significantly smaller than the 2-month impacts, and are not statistically different from zero. We examine treatment heterogeneity using the traditional interaction approach, by examining quantile treatment effects, and using the generic machine learning approach of Chernozhukov et al. (2020). There is limited predictable heterogeneity in treatment impacts, and we do not find any subgroup has lasting treatment impacts. This lack of persistent impact appears to reflect both the treatment group stopping doing some of the business practices it had adopted, as well as some control group catch-up. In a changing business environment, training appears to have sped up the process of getting firms to examine their records and make budgets, but since it did not significantly improve their marketing or personal initiative, this may explain why it was unable to generate sustained increased in sales.

This paper contributes to literatures on interventions to help the self-employed, and on remote education and training. The main contribution is to the literature on improving business practices and management in firms, reviewed in McKenzie et al. (2021). The majority of this literature has focused on in-person training programs that can be hard to scale. Improvements in digital technology combined with the COVID-19 pandemic have led to different approaches to testing digital delivery. One approach has been to use asynchronous content. For example, Jin and Sun (2021) offer short training tasks to Chinese online sellers, and Estefan et al. (2023) offer 1-7 minute video capsules to Guatemalan chicken franchise owners. Such an approach can scale cheaply, but tends to be short in duration limiting what can be taught, does not allow for interaction with an instructor, and can suffer from low take-up: only 12.6 percent of sellers in Jin and Sun’s study finished even one task. An-

> 1However, this comparison disregards the greater geographic spread allowed by online training, which would be prohibitively costly with in-person training.

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