Several experimental studies have compared the prevalence of sensitive health behaviors between ACASI and face-to-face survey methods. Most found that respondents reported sensitive health behaviors and experiences, including IPV, at higher rates under ACASI than the face-to-face method, though the evidence is mixed (Fay et al., 1998; Jaya, Hindin and Ahmed, 2008; Langhaug, Sherr and Cowan, 2010; Mensch et al., 2008; Phillips et al., 2010; Fincher et al., 2015). In one of the few method comparisons with an objective indicator, in Brazil, Mensch et al. (2008) compared sexually transmitted infection bio-markers with face-to-face and ACASI self-reports of risky sexual behavior. They found more underreporting when respondents were interviewed face-to-face than with ACASI.

# **2.2 More Confidentiality and Anonymity: List Experiment**

Researchers have also used the list experiment to improve data accuracy when measuring sensitive behaviors and attitudes.<sup>8</sup> The standard list experiment works as follows: respondents are randomly assigned to one of two groups to answer the list question. In the ‘non-sensitive’ or ‘control’ group, enumerators read respondents a set of three non-sensitive statements and ask the respondent to tell them how many but not which statements are true for the respondent, with possible answers between zero and three. Meanwhile, the ‘sensitive’ or ‘treatment’ group is read the same list of statements, with the addition of a fourth sensitive statement. They are given the same instructions, to say how many, between zero and four statements, are true. Given the sensitive and non-sensitive list groups are randomly assigned, the two groups are, in expectation, equivalent and the only difference is the inclusion of the sensitive statement. The prevalence of the sensitive item across the whole sample is thus the difference in the mean number of items reported by the two groups.

Unlike with the ACASI and face-to-face methods, anonymity is assured because the lists are designed in such a way that very few people in the list sensitive group have all four statements as either true or not true.<sup>9</sup> This way, a respondent is not revealing their true answer to the sensitive item- to the enumerator or anyone with data access. This could mitigate underreporting by respondents concerned about consequences if someone were to find out their answers, or those who doubt the confidentiality of their data, or who find it easier to truthfully admit sensitive answers when asked indirectly.

Ex-ante, it is not clear whether shame or fear would be the biggest driver of misreporting on IPV survey questions. Assuming that responding in the affirmative is stigmatized, if the shame from answering a question face-to-face dominates other motivations for underreporting, then reporting is likely to be greatest under ACASI. If concerns about being identified or fear of potential repercussions dominate, then reporting would likely be greatest under the list experiment.

There are potential drawbacks to the list experiment. One challenge is that, by design, it cannot be used to identify individuals who respond affirmatively to the sensitive question of interest, potentially limiting its use where individuals need to be referred to support services, for example. Also, with list experiment answers ranging from zero to four, it typically has greater variance than direct questioning

> 8For example, Miller (1984) developed the list method to study illicit drug use. Others have used it to study sensitive topics including prejudice in the United States (Kuklinski, Cobb and Gilens, 1997), political preferences in Lebanon (Corstange, 2009), support for militant groups in Afghanistan (Blair, Imai and Lyall, 2014), risky sexual behavior (Chuang et al., 2018; Jamison, Karlan and Raffler, 2013; Lépine et al., 2020), support for female genital cutting (De Cao and Lutz, 2018), vote buying (Gonzalez-Ocantos et al., 2012), and use of microfinance loans (Karlan and Zinman, 2012).

> 9This can be done through careful piloting and selecting a set of statements that are all plausible but where the cooccurrence of all being true or untrue for any one person is unlikely. See Glynn (2013) and Corstange (2009) for a discussion and suggestions.

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