摘要:We analyze the effect of open access (OA) status of journal articles on citations. Using cross‐sectional and panel data from mathematics and economics, we perform negative binomial, Poisson, and generalized method of moments/instrumental variable methods regressions. We benefit from a natural experiment via hybrid OA pilot agreements. Citations to pre‐prints allow us to identify the intrinsic quality of articles prior to journal publication. Overall, our analysis suggests that there is no hybrid OA citation benefit. However, for the subpopulation of articles without OA pre‐ or post‐prints, we find positive hybrid OA effects for the full sample and each discipline separately. (JEL L17, O33, A11)