Getting cited: Does open access help?

Cross-sectional studies typically find positive correlations between free availability of scientific articles (‘open access’) and citations. Using a number of instruments as plausible sources of exogeneous variation, we find no evidence for a causal effect of open access on citations. We provide theory and evidence suggesting that authors of higher quality papers are more likely to choose open access in hybrid journals which offer an open access option. Self-selection mechanisms may thus explain the discrepancy between the positive correlation found in Eysenbach (2006) and other cross-sectional studies and the absence of such correlation in the field experiment of Davis et al. (2008).