This analysis of book records and holdings in WorldCat finds that the overlap of global book collections among ARL libraries is not as extensive as expected. The analysis found that, on average:
* For all countries combined, fewer than five ARL libraries own copies of any foreign-imprint book represented in WorldCat.
* When the same data are examined by world regions, excluding North America, the overlap in holdings ranges from three to six ARL libraries. On average, three ARL libraries hold any given East Asian book and six hold any given book published in Latin America.
A closer examination was made of books from 10 countries (excluding North America) most represented in ARL library collections: United Kingdom (UK), Germany, France, Japan, Italy, China, Spain, Russian Federation, India, and the Netherlands. On average, holdings from these countries decreased in each of the five-year increments between 1980 and 2004, with the exception of books published in the UK that showed a slight increase.
From the Conclusion:
The relative low average number of holdings per record for many countries and for many time periods suggests that libraries build and maintain collections that reflect local academic programs and faculty research interests or areas of historical strength. On the other hand, the low average number of holdings may also suggest that libraries have been fairly successful in formal or informal collaborative collection development efforts. Finally, the low number of holdings argues for the need for effective interlibrary loan and document delivery services as faculty and students are not able to find all materials in their local or consortia libraries. The downward trajectory in the average number of holdings identifies a decrease in the number of titles research libraries are adding to WorldCat and possibly to their collections.