Navarro, Peter. "Why Do Corporations Give to Charity?" Journal of Business, January 1988.
LK comment: Reviews corporate giving data for 249 U.S. firms for 1978, 1981 and 1983. Finds that contributions were negatively related to firm debt and positively related to firm dividends. Argues that profit maximization "is an important motive driving contributions."
This was one of the first papers to directly study the characteristics and motivations for corporate charitable giving. Thirty years on, our understanding of this topic is still quite limited.
See also Diltz (1995b) and Zivin and Small (2005).