برآورد اثرات همسالان در رفتار جنسی در میان نوجوانان
|کد مقاله||سال انتشار||مقاله انگلیسی||ترجمه فارسی||تعداد کلمات|
|35898||2011||8 صفحه PDF||سفارش دهید||محاسبه نشده|
Publisher : Elsevier - Science Direct (الزویر - ساینس دایرکت)
Journal : Journal of Adolescence, Volume 34, Issue 1, February 2011, Pages 183–190
In this paper we seek to empirically quantify the role of peer social networks in influencing sexual behavior among adolescents. Using data of a nationally representative sample of adolescents we utilize a multivariate structural model with school-level fixed effects to account for the problems of contextual effects, correlated effects and peer selections to purge the potential biases from the estimates of peer influence. Our peer group measures are drawn not only from the nomination of close friends, but also from classmates. Controlling for parent level characteristics, and other demographic parameters, we find that a 10% increase in the proportion of close friends who initiates sex increases the probability that an individual chooses to initiate sex by 5% and a 10% increase in number of sexual partners among close friends increases an individual's sexual partner by 5%. The influence of classmates however, diminishes in magnitude after accounting for unobserved environmental confounders.
An increase in the percentage of adolescents engaging in sexual intercourse accompanied with a decrease in the age of sexual initiation have occurred during the last 30 years (Seiverding, Adler, Witt, & Ellen, 2005). The number of sexual partners before the age of 18 has also been steadily rising (Davis & Friel, 2001). Even though sexuality is a normative event and considered a normal aspect of healthy adolescent development (Brendgen, Wanner, & Vitoro, 2007), early initiation of sexual behavior is associated with adverse health and educational outcomes such as sexually transmitted diseases (STD), poor mental health (Sabia & Rees, 2008), lower grade-point averages (Sabia, 2007) and unintended pregnancies (Davis & Friel, 2001). Early fertility is associated with negative educational and subsequent labor market outcomes and also has intergenerational effects; children of teenage mothers are less likely to receive good prenatal care, are relatively disadvantaged and are more likely to repeat the behavior (Trussell, 1988). A large literature has been devoted to determine the importance of social networks in influencing adolescent behaviors, especially health risky behaviors and outcomes (Ali and Dwyer, 2009, Bearman and Moody, 2004, Guo et al., 2009, Jaccard et al., 2005 and Valente et al., 2009). In the case of adolescent sexual behavior, the role of social networks or peer effects are unclear (Fletcher, 2007), but there exists some evidence to suggest that behavioral choices by adolescents are partly determined by how acceptable the behavior is believed to be among their peers (Evans, Gilpin, Farkas, Shenassa, & Piere, 1995). For example, an adolescent's self-reported perception of friends' sexual behavior has been identified as an important predictor of sexual initiation (Romer et al., 1994 and Teitler and Weiss, 2000). The flow of STD in social networks has also been documented (Moody, 2002). Regardless of the mechanism through which social influences affect adolescent sexual behavior, for example information sharing and the development of social norms (Fletcher, 2007); from a policy perspective, the potential existence and the magnitude of the social network effect is of interest since “peer effects may serve to amplify the effects of interventions” (Lundborg, 2006, p. 215). Thus it is important to understand the social process that influence sexual behavior so that prevention policies can be designed to incorporate such influences (Romer et al., 1994). Peer effects, however, are difficult to estimate and causal interpretations must be undertaken with caution since individuals in most cases choose with whom to associate (Kremer & Levy, 2008). In other words, estimates without accounting for peer selection are unable to identify accurately whether an individual's behavioral choices in some way varies with behavior of the reference group (Manski, 1993). Peer selection implies that the correlation in behavior could be attributed to the similarity among individuals, whereas, peer influence implies that the correlation is due to the peer behavior. Disentangling the peer influence from spurious unobserved factors, associated with peer selection is important if we are to accurately predict the success of policies aimed at reducing any risky behavior among adolescents. Thus, if there are common underlying attributes of individuals within a peer group that drive behavior more than peer influence, policies aimed at taking advantage of peer influence may not realize the desired effects. Building on the existing literature on peer effects we extend our analysis by empirically quantifying the role of peer social networks to explain sexual behavior among adolescents. Constructs of sexual behavior in our study includes sexual initiation and the number of sexual partners. Our peer measures are drawn not only from the nomination of close friends, but also from classmates within a grade. This allows us to identify the differences in effects that could be exerted by different compositions of the reference groups. Further we implement two stage least square modeling approaches with school-level fixed effects to purge potential biases from the peer estimates in order to give it a causal interpretation.