 "We estimate the causal effect of open access to academic journal articles on article downloads by exploiting a natural experiment in which the paywall to several prestigious educational research journals was unexpectedly taken down for two months. Using the always open-access ''AERA Open'' as a control group, we find credibly causal evidence that removing the paywall increased monthly downloads by 00 to 00%." There's reason to think that many of the new readers were not professional researchers. "[I]n the case of educational research, citations are not necessarily the correct measure of impact, as teachers, schools, and districts may use journal articles to inform their policy and practice without ever formally citing the research." 