# **5 Results**

## **5.1 Samples Characteristics and Randomization Checks**

Tables D3 and D4 in the Appendix describe the characteristics of the individuals and households in the experience and cross-sectional samples, respectively. The tables report the variables’ means in the treatment and control conditions, their normalized difference<sup>32</sup> and the _p-value_ associated to the t-test for their comparison. For the experience sample, we report both covariates (Panel A) and main outcomes (Panel B) measured at baseline (i.e., during the first survey wave). For the cross-sectional sample, conducted after campaign completion, we only report time-invariant covariates.

Both tables exhibit a general balance in baseline individuals’ and households’ characteristics and pre-treatment outcomes across experimental groups, validating the randomization process. For the longitudinal (experience) sample, none of the differences between treatment and control groups is significant. In the cross-sectional sample, the treatment group happens to include a slightly higher proportion of unemployed individuals and households with pregnant women compared to the control group. However, these disparities are minor, and we address them in the analysis by incorporating these and other factors as controls in the regressions.

In both samples, respondents are roughly evenly split among treatment and control districts, and approximately 55% of them reside in non/semi-solid dwellings, reflecting a successful implementation of the stratified recruitment across districts and dwelling type. Attrition in the experience sample was equally balanced across experimental groups, with respondents completing 3 survey waves, on average. In terms of socio-demographics, males make up about 90% of the samples, with an average age of 27 years, and 55% to 60% report university completion, while about a half indicate being unemployed. Around 60% of the respondents identify with socially and economically disadvantaged castes (OBC, SC/Dalit and ST), which prior studies suggest exhibit a lower awareness regarding malaria prevention (Singh et al., 2020). Household size ranges between 6 and 7 members. One of every eight households is home to a pregnant woman. Three-quarters of participants reside within 60 minutes (by walk) of a medical center, and a similar proportion has a mosquito net at home.

In terms of outcomes, 2% of respondents report a household member having experienced malaria in the past two weeks (and 20% within the last five years). About 70% of those with a bed net at home report having used it the previous night, with about 70% of household members sleeping under it. Combining these numbers with the average bed net ownership in the sample (75%) suggests that just over 50% of individuals are regularly protected from mosquito bites at night. Relatedly, approximately one-third of the participants express some level of concern about getting malaria in the following month.

As expected, our online sample exhibits a higher socioeconomic status compared to the general population. This is highlighted by population-level statistics from the 2019-2021 India Demographic

> 32The normalized difference is the difference between the two means divided by the square root of the sum of the variances of the two variables.

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