Homer Hoyt, 89, a land planner, housing and real estate economist and author whose marketing research helped to frame much of the development in the Washington suburbs over the last 30 years, died of pneumonia Nov. 29 at Holy Cross Hospital. He lived in Silver Spring.

Dr. Hoyt's economic studies of Washington's Maryland and Northern Virginia suburbs during the 1950s forecast the rapid growth that materialized over the next decade.

He advised Fairfax County in 1953 to develop a regional shopping center. His 1954 economic survey of Montgomery and Prince George's counties predicted heavy population and economic growth would deluge those largely agricultural areas during the next 25 years. He also urged Arlington County in the mid-1950s to put greater emphasis on the expansion of its commercial areas.

Dr. Hoyt established Homer Hoyt Associates, his economic consulting firm, in New York City in 1946. He moved to Washington in 1953 and became one of the area's leading land and real estate economists. He specialized in shopping center planning and did the marketing research for more than 200 facilities, including Wheaton Plaza.

In 1967, he founded the Homer Hoyt Institute, a nonprofit organization that makes grants to universities for research on urban growth and land planning. Since 1974, Dr. Hoyt had been primarily involved in real estate investing.

Dr. Hoyt was born in St. Joseph, Mo. He graduated from the University of Kansas. He earned a law degree and a doctorate in economics from the University of Chicago. He taught economics and was a real estate broker in Chicago before joining the Federal Housing Administration as a housing economist in 1934. He held economic planning positions in Chicago and in New York City before he moved to Washington.

His books include, "100 Years of Land Values in Chicago," "Structure and Growth of Residential Neighborhoods in American Cities," and "Principles of Real Estate," of which he was a coauthor.

He received the George L. Schmultz Award from the American Institute of Real Estate Appraisers, of which he was a member. He also received the Distinguished Service Award of Lamda Alpha, the international land economics fraternity.

Dr. Hoyt was a member of the American Economists Association and the Washington Real Estate Board.

His wife, Gertrude Hoyt, died in 1975.

Survivors include one son, Michael, of Silver Spring; a stepson, Eugene McGuane of Fort Lauderdale, Fla.; a stepdaughter, Alice Collins of Chicago, and nine grandchildren.