Ten-Year Cross-Disciplinary Comparison of the Growth of Open Access and How it Increases Research Citation Impact Chawki Hajjem, Stevan Harnad, and Yves Gingras   View Paper (PDF)   Return to December 2005, Searching and Mining Literature Digital Libraries, Volume 28, Number 4 Abstract .005). Causality cannot be determined from these data, but our prior finding of a similar pattern in physics, where percent OA is much higher (and even approaches 100% in some subfields), makes it unlikely that the OA citation advantage is merely or mostly a self-selection bias (for making only one's better articles OA). Further research will analyze the effect's timing, causal components and relation to other variables, such as, download counts, journal citation averages, article quality, co-citation measures, hub/authority ranks, growth rate, longevity, and other new impact measures generated by the growing OA database. ©2006 Association for Computing Machinery