Three essays in risky behaviors

A PhD Dissertation, presented as part of the requirements for the Degree of Doctor of Philosophy from the NOVA - School of Business and Economics

This dissertation consists of three essays on the relationship between risky behaviors and social environment, including the strategic construction of conversational networks to discuss HIV related issues, the impact of social stigma on risky behaviors, and how subjective expectations from parents can influence childhood obesity. Understanding where people seek information and how they react according to the social environment is shown to be important in designing effective prevention policies and programs. In the first chapter we investigate the formation of informal HIV conversational networks in rural Malawi. Using data from the Malawi Longitudional Study of Familes and Health (MLSFH), which contains detailed data on conversational networks, we compare the overlap of conversational partners between the network formed to discuss family planning and the one formed to discuss HIV-related issues. If networks were constructed randomly, there should be a high overlap in the composition of different networks for the same individual, as the establishment of a social link is costly. We find evidence that points toward a strategic behavior of individuals by concluding that people (1) vary the composition of their networks; (2) select partners to talk with about HIV who are able to provide them with new information, and (3) both men and women who perceive themselves to be less likely to be infected or to be less exposed to HIV risk consistently look for partners who can provide them with better information. The second paper is a joint work with Adeline Delavande and Neeraj Sood. We estimate the causal effect of social stigma against HIV+ persons on risky sexual behavior in rural Malawi by using plausibly exogenous variation in stigma arising from the introduction of a radio campaign seeking to reduce social stigma. The effect of stigma on risky behavior is a priori ambiguous. On the one hand, higher stigma can lead people to disassociate from the stigmatized group and hence promote risky behavior. On the other hand, stigma can be viewed as a social tax on being HIV+ and higher stigma may reduce risky behavior as a result. We find that an increase in social stigma is associated with an increase in risky behavior, including more partners and a higher likelihood of having extra-marital relations. This effect is mainly driven by the impact of stigma on men. The third chapter of this dissertation tackles the childhood obesity epidemic, by introducing two new approaches: the subjective expectations that parents have about the probability of future childhood obesity conditional on their choices of energy intake and expenditure, and the distribution of decision-power within the household. To identify these two new explanations for childhood obesity we designed and administered a survey in seven primary schools that resulted in an unique dataset covering three districts from Portugal and 220 respondents. Evidence points to the conclusion that parents have accurate expectations about the impact of consuming soft drinks and having an active life. Nevertheless, parents tend to believe that limiting soft drink consumption plays a more important role in fighting childhood obesity, and under-value the importance of physical exercise. This leaves room for policy making in promoting the right balance in the energy intake and expenditure. Moreover, we show that parents who have a higher decision-power within the household and those who perceive a higher increase in the probability of obesity when increasing soda consumption, are the ones whose children drink less of such beverages. All in all, this dissertation contributes to the literature of risky behaviors by shedding some light about how the social environment shapes individuals' attitudes and perceptions toward risky behaviors. Not only do people deliberately seek information, they also tend to opt for less risky behaviors when they have a clear image of the risk they face and they live in a tolerant society. This suggests that working on the quality of the society's values and information flow as a whole, could trigger a reduction in risk taking behaviors at the individual level.