Since the nonprofit Online Computer Library Center created WorldCat 40 years ago, librarians around the world have filled the database with bibliographic information on more than 1.75 billion items from 72,000 libraries in 170 countries.
Librarians use the database to access information on any book in the global stack. Borrowers can search WorldCat’s mobile app for books, movies, maps, music and research papers in nearby libraries. Researchers, meanwhile, can mine WorldCat to uncover historical and cultural trends, and perhaps predict future ones. A University of Toronto economist, for example, found that spikes and drops in the number of new technology books tend to precede economic expansions and recessions (respectively) by approximately one year.