The Effect of Free Access on the Diffusion of Scholarly Ideas :
“This study examines a relationship between free access to research articles and the diffusion of their ideas as measured by citation counts. While free access should, in theory, help the diffusion of ideas, many researchers have debated the existence of the benefit of free access: reported empirical findings range from zero or negative effect to an over 300% increase of citations of non-free articles. By using a dataset from the Social Science Research Network (SSRN), an open repository of research articles, and employing a natural experiment that allows the estimation of the value of free access separate from confounding factors such as early viewership and quality differential, this study identifies the causal effect of free access on the citation counts. The natural experiment in this study is that a select group of published articles is posted on SSRN at a time chosen by their authors’ affiliated organizations or SSRN, not by their authors. Using a difference-in-difference method and comparing the citation profiles of the articles before and after the posting time on SSRN against a group of control articles with similar characteristics, I stimated the effect of the SSRN posting on citation counts. The articles posted on SSRN receive more citations even prior to being posted on SSRN, suggesting that they are of higher quality. Their citation counts further increase after being posted, gaining an additional 10-20% of citations. This gain is likely to be caused by the free access that SSRN provides.”
URL : http://mis.eller.arizona.edu/events/speakers_series/2012/mis_speaker_series_Heekyung_Kim.asp