Siddique et al. (2024) report large effects of a mobile phone-based health awareness campaign in a field experiment conducted in rural Bangladesh and India during the COVID-19 pandemic. Treatments are stated as being randomized at the village level in the Bangladesh arm, but analyses of available replication materials from this and related field experiments show that this was not the case: participants retained their treatment group assignment from two earlier studies run by the same NGO. Because these earlier studies reported large and persistent treatment effects, the treatment groups in Siddique et al. (2024) could plausibly differ systematically, raising issues of confounding and interaction effects that invalidate the analyses and interpretations of this study, affecting both internal and external validity.

Montero (2022) explores a discontinuity in a land reform in El Salvador and reports two main findings. First, relative to outside-owned haciendas operated by contract workers, the productivity of worker-owned cooperatives is higher for staple crops and lower for cash-crop. Second, cooperative property rights increase workers' incomes and compress wage distributions. In this comment, we show that the latter result rests on two mistakes: three-quarters of the observations are duplicates and income inequality is calculated over too few workers to be meaningful. When corrected, the data sources and research design provide no credible evidence regarding the causal effects of ownership structure on income levels and inequality.