A study conducted by the copy editor of a small daily newspaper in Porter County, Indiana examines readers' motivations for writing letters to the editor. Analysis was based on letters that appeared in "The Vidette Messenger" September 16-30, 1992. Of 75 letters, 32 were responses to information published in the paper during the last 2 weeks. All but one of these addressed local issues. These letters concerned four basic topics: the family, the environment, money matters, and corrections of newspaper errors. The family-oriented opinions, the most often addressed topic, were responses to four articles. These articles concerned a cat leash law under debate in the community, a poor single-parent family, abortion, and family size and overpopulation. Five of seven letters written about the environment were responses to letters written by other readers. Five of seven letters written about money matters discussed the potential use of a County Option Income Tax; two concerned housing and health care. From this sampling, 25 letters (43.9%) were not responses to readings. These fell into two categories: letters dealing with the upcoming presidential election and informational and persuasive letters. Of all opinions published within the 15-day period, 76% were written by non-paid and non-professional authors. The study showed that letters to the editor tend to address local, personal concerns. Newspapers, which must compete in a marketplace increasingly dominated by electronic media, should take note that readers have the strongest response to local issues that affect them personally. (A graph and a table of data are included; attached appendix contains newspaper articles and sample letters.) (SAM)