Heather Morrison, The Dramatic Growth of Open Access: March 31, 2006 Update, Imaginary Journal of Poetic Economics, March 31, 2006. Excerpt: In the last quarter, over 780,000 records have been added to OAIster, suggesting that those open access archives are beginning to fill! There are 170 more titles in DOAJ, likely an understated increase due to a weeding project. 78 titles have been added to DOAJ in the past 30 days, a growth rate of more than 2 new titles per day. Disciplinary archives are showing remarkable growth. E-LIS has been increasing at the equivalent of 56% annually. Differences in growth rates suggest the possibility of a life-cycle factor in open access archives growth, perhaps initial slow growth, followed by very rapid growth, then a more steady growth as the archive matures....The most notable increase is the addition of over 780,000 records to OAIster, the equivalent of a 50% annual increase. This rate of increase doubles that of 2005 (25%). This evidence suggests that those open access institutional archives are beginning to fill! Among the disciplinary archives examined, the highest growth rate was shown at E-LIS, with an equivalent of a 56% annual increase. The longer-established disciplinary archives showed impressive but slower growth rates: RePEC, 25%, and arXiv, 12%. One possible explanation could be a life-cycle factor for successful disciplinary archives, with a relatively high percentage growth rate at an early stage, followed by slower percentage growth at a more mature phase. This will reflect, in part, the larger size of the repository. It takes more records to create a 12% increase in a large repository than a 50% increase in a small one. Data from the Canadian Metadata Harvester may indicate another potential life-cycle effect. That is, the Canadian repositories showed a growth rate equivalent to less than 12% per year. The difference between the Canadian open access archives data increase and the OAIster increase (50%) may reflect the relative newness of many of the Canadian repositories. While delayed free access is not true open access, the 200,000 articles added to the Highwire Free program - an equivalent of a 72% annual increase - does represent a dramatic increase in free access. DOAJ includes 170 more titles now than on Dec. 31, 2006, an equivalent annual growth rate of 34%. This percentage is likely an understatement, as DOAJ has been undertaking a weeding project to remove titles no longer