Former Harvard Business School (HBS) Professor Jesse W. Markham, an economist whose work focused on price theory and industrial organization, died in his sleep on June 21 in Nashua, N.H., at an assisted-living home. He was 93.

By the time he joined the HBS faculty in 1968 from Princeton University, where he had been professor of economics, Markham was a well-known proponent of the “rule of reason” to determine whether a merger should pass muster under federal antitrust laws. “Unlike those who advocated following arbitrary guidelines regarding industry concentration and market share,” he said in a 1993 interview at the School, “I preferred to look at each case on its own merits.”

A major study Markham undertook at HBS supported that point of view. Published in 1973, Conglomerate Enterprise and Public Policy was a detailed examination of more than 200 large corporations that had diversified during the merger mania of the 1960s. Although companies such as Textron, Gulf & Western, and International Telephone and Telegraph (ITT) were acquiring a mixture of other firms during that decade, Markham found no enhancement of “market power” in any of the diverse industries in which these conglomerates operated.

It was the opportunity to deal with these kinds of problems that led Markham to accept Dean George P. Baker’s invitation to teach and do research at Harvard Business School. “I came here because the theories on which public policy was being built in economics didn’t square with the realities of the marketplace,” he once observed. “I wanted to work in an environment where my colleagues, students, and contacts were close to managerial decision making.”

Appropriately, Markham’s first classroom assignment at HBS was in the School’s Advanced Management Program (AMP), where he taught a survey of international trade problems and public policies affecting American business. In the M.B.A. program, he offered a second-year elective called “Marketing and Public Policy,” and from 1978 to 1982 he served as head of “Creative Marketing Strategies,” a field study course that put student teams to work on issues facing actual clients.

Markham was born in Sharps, Va., on April 16, 1916. He traced his interest in economics to his sophomore year at the University of Richmond, where he won praise from a professor for his work in an introductory class. Encouraged to continue his studies in the field, he opted to major in economics rather than engineering. Excelling in the classroom and on the baseball diamond, he received his bachelor’s degree in 1941 as a member of Phi Beta Kappa. He began graduate school in economics that fall at Johns Hopkins University.

When a fellowship enabled him to spend part of the year doing research in Boston, Markham sat in on some courses offered by the Harvard Economics Department. Although World War II interrupted his education in 1942, his experience in Cambridge made a lasting impression. After three years as an officer in the U.S. Navy, where he saw combat as a gunnery officer on a heavy cruiser, he decided to return to Harvard to resume his academic career. He earned a master’s degree in 1947 and a Ph.D. two years later.

Markham’s first faculty appointment was at Vanderbilt University. In 1953, however, as he was about to take a position at Princeton, the Federal Trade Commission (FTC) selected him to be its chief economist. “At a time when Congress had passed an act putting arbitrary constraints on corporate mergers,” Markham said, “the Eisenhower administration saw me as a voice in favor of a standard of workable, as opposed to perfect, competition. I could advocate the benefits of letting certain firms work together to foster innovation, which buyers value just as much as temporary price advantages — the traditional yardstick of competitiveness.”

Leaving the FTC in 1955, Markham finally took his place at Princeton, where he taught for more than a decade, except for stints as a visiting professor in the Harvard Economics Department and at HBS. Three years after heeding Baker’s call to stay at Harvard permanently in 1968, Markham was named the School’s Charles E. Wilson Professor of Business Administration. He retired from the active faculty in 1982, but went on to teach for two years at Emory University. He was also a member of the Harvard Extension School faculty for many years. “I have always been energized by my work with students,” he explained.

Markham authored 12 scholarly books and more than 150 articles. In 1994, Harvard Business School honored him with a Distinguished Service Award. The citation he received read in part: “Honored scholar and master of merger policy, you have been trusted by professors and presidents to analyze the pros and cons of corporate combinations. … Your love of teaching has been legend, your admirers legion, and your publishing prolific. Never a retiring sort, you have been a rich resource to all of Harvard, a steady guide in the constant search for VERITAS.”

Markham is survived by his wife of 65 years, the former Penelope Anton; three children, Elizabeth (Betsy) McLean of Merrimack, N.H., John James Emmanuel II of Boston, and Jesse William Jr. of San Francisco; a niece, Penny Boling of Manchester-by-the-Sea, Mass.; six grandchildren; and six great-grandchildren.