Knowledge Access: The Effects of Carnegie Libraries on Innovation

Abstract

Between 1883 and 1919, Andrew Carnegie funded the construction of more than 1,500 public libraries across the United States, reducing the costs of accessing knowledge for millions of people. We study the effect of these libraries on innovation using new data on city-level patenting and a novel control group: cities that qualified to receive a library grant and applied to be part of the program, but ultimately did not build a library. Patenting in recipient towns increased by 7-11 percent in the 20 years following library construction. We show that access to scientific knowledge and opportunities to interact with fellow patrons are possible mechanisms.