Three pieces of evidence lead us to believe that our results are not driven by experimenter demand effects. First, the point estimates of our treatment effect on objective and subjective indicators for HIV testing are very similar at 0.031 and 0.025, respectively (see Table 2). In the presence of experimenter demand effects, one would expect the latter coeffi cient to be larger.

Second, many relevant self-reported outcomes do not display significant treatment effects. Notably, we find no effects on self-reported condom use (Panel B of Table 3) and on five other condom-related variables (Appendix Table A16).

Third, if treated individuals were differentially affected by reporting bias, we should find that when they have a chance of pleasing the research team by choosing condoms in the experimental game played in health camps, they should be more likely to do so. Panel A of Table 4 shows that this was not the case.

Heterogeneous effects by education and language. An interesting question is whether our effects differ depending on viewers’level of education or ability to understand English (as MTV Shuga was in English). In Appendix Table A25 we interact the treatment dummy with the respondent’s years of education (odd-numbered columns) and with a dummy for whether respondent speaks English as the primary or secondary language at home (even-numbered columns). The average respondent in our sample has 11.6 years of education, and 96 percent of the respondents speak English at home as either primary or secondary language.<sup>35</sup> We find that Shuga had a stronger effect on HIV knowledge and attitudes of relatively more educated respondents, although the coeffi cient on the interaction term with education is not significant when adjusting for multiple hypothesis testing. This may seem surprising as one may expect television to be a particularly effective means of communication for audiences with low literacy, but it should be noted that ours is a uniformly highly educated sample, as is the region.<sup>36</sup> So it is plausible that the education effect we uncover reflects the fact that the message of Shuga was relatively progressive.<sup>37</sup> No robust effects are found for the interaction between treatment and speaking English at home, possibly because the latter variable has very little variation in our sample.

# 8 Conclusions

In this paper we have tested the effectiveness of an entertainment education TV series, MTV Shuga, aimed at providing information and changing attitudes and behaviors related to HIV.

> 35 Note that English is the language of instruction in schools and is the only offi cial language in the country.

> 36 The high level of education is not an artifact of our sample: the average respondent in the 2008 Nigeria DHS (of similar age and living in the South West) had 11 years of education.

> 37 Note that despite the negative coeffi cient on the standalone treatment dummy, the overall effect of treatment is abundantly positive when evaluated at the mean years of education. For example, ceteris paribus the impact on knowledge is positive for any respondent with at least 9.5 years of education, which corresponds to the 4th percentile in the distribution of education.

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