THE IMPACT OF HIV EDUCATION ON BEHAVIOR AMONG YOUTHS: A PROPENSITY SCORE MATCHING APPROACH

I. INTRODUCTION Approximately 1.1 million people in the United States were living with human immunodeficiency virus (HIV) in 2006 (Centers for Disease Control and Prevention [CDC] 2006). Nearly 30% of new HIV infections occur in people under the age of 30 and the majority of young people are infected through sex (Hall et al. 2008; Kaiser Family Foundation 2005). Furthermore, adolescents represent a high-risk group for contracting HIV and other sexually transmitted infections (STIs) (Hopkins, Tanner, and Raymond 2004). Despite the fact that 15-24 year olds represent only 25% of the U.S. population that is sexually active, these individuals account for nearly one-half of all new STIs (Weinstock, Berman, and Cates 2004). Because risky sexual behavior increases the likelihood of contracting HIV and STIs, school-based sex and HIV educational courses represent potential policy instruments for affecting transmission rates among adolescents. Moreover, in promoting safer sex, causing a decrease in the frequency of intercourse, and/or delaying the sexual debut of youths, these programs could have positive effects beyond decreases in HIV and STI rates. Early virginity loss and sexual promiscuity have been shown to share a negative relationship with educational attainment, while the delay of one's sexual debut has been shown to be positively related to psychological well-being (Sabia and Rees 2008, 2009, 2012). (1) A reduction in risky sexual behavior may also decrease the incidence of teenage pregnancy. Evidence suggests that teenage pregnancy impedes the accumulation of human capital and decreases future earnings (Hoffman, Foster, and Furstenberg 1993; Klepinger, Lundberg, and Plotnick 1999; McElroy 1996; Rosenzweig and Wolpin 1995). (2) Lastly, these courses may provide adolescents with a better understanding of human physiology and relationships (Marsiglio and Mott 1986). The aim of this study is to examine the impact of school-based HIV education on risky behavior among youths. There are reasons to expect a negative relationship between HIV education and risky behavior. HIV education provides pertinent information to protecting oneself from contracting the virus. Information on the use of contraceptives, for example, may increase the probability a teen practices safe sex. Accurate information regarding the probability of contracting HIV and the consequences associated with infection can also be used by the individual when deciding whether or not to engage in sexual activity. If an individual's prior perceptions understate the true costs of sex, then we might expect HIV education to decrease the frequency of intercourse. On the other hand, a positive relationship between HIV education and sexual activity may exist. If HIV education promotes the use of contraceptives, this could lead to an increase in protected sex but also to an increase in intercourse frequency because of a decrease in the perceived costs of sex. It is also possible that HIV instruction increases sexual activity by sending a signal of social approval of sex. Opponents typically criticize contraception-based HIV education on these grounds and either support abstinence-only programs or no school-based education at all (Collins, Alagiri, and Summers 2002). To estimate the effect of school-based HIV instruction on youth behavior, this paper uses data from the 2009 Youth Risk Behavior Survey (YRBS). Findings from a propensity score matching (PSM) analysis suggest standard ordinary least squares (OLS) results are biased. Despite this, there remains some evidence that exposure to HIV education is negatively related to sexual activity, and this result is strongest for males. There is also evidence that exposure to HIV education reduces the rate of needle use among male students. A Rosenbaum bounds sensitivity analysis illustrates the needle use results are robust to differing assumptions about the degree to which unobserved selection bias may remain in the PSM estimates. …