Are estimated peer effects on smoking robust? Evidence from adolescent students in Spain

Adolescent smoking is one of the most pressing public health problems. The objective of this paper is to analyse the influence of peer pressure on adolescent cigarette consumption. More concretely, we explore the significance and robustness of the peer effects using several estimation methods employed in the existing literature. On the basis of the data provided by the 2004 Spanish survey on drug use in the school population, we estimate the probability of being a smoker by two-stage models. The results reveal that when we use standard errors used in the literature the class peer variable appears to be significant. However, the class peer variable is not significant when we calculate more exigent standard errors, a result that is robust across all specifications. The paper suggests the need for a more cautious interpretation of the peer effects found previously in the literature until a deeper analysis confirms the robustness of the peer effects.