Dorothy S. Brady, 73, an economist and retired professor of the Wharton School of Finance and Commerce, died Sunday at her home in Pine Hill, N.Y. She had suffered from a heart ailment.

She was known for her work on distribution of personal income and savings. She had been an active member of the Conference on Research in Income and Weach of the National Bureau of Economic Research for 30 years.

Dr. Brady joined the staff of the U.S. Bureau of Labor Statistics as chief of its cost of living division in 1943. She formulated the concept underlying the first City Workers Family Budget, published in 1947.

After serving on the faculty of the economics department of the University of Illinois from 1948 to 1951, she rejoined the Bureau of Labor Statistics.

In 1955 and 51956, Dr. Brady was a visiting professor at the University of Chicago. She then became a professor at the Wharton School of the University of Pennsylvania until retiring in 1970. She continued as a consultant to the Wharton School until 1974.

Dr. Brady, who grew up in Portland, Ore., was a graduate of Reed College and received a doctorate in mathematics from the University of California at Berkeley.

She taught at Wassar College and the University of New York. She first worked for the federal government as an economist and statistician in the bureau of home economics of the Agriculture Department from 1936 to 1943, when she wrote numerous reports on the expenditures and savings of rural families.

In 1949, she wass elected a fellow of the American Statistical Association for her work on family budgets.

From 1964 until 1971, she was a consultant to the office of research and statistics of the Social Security Administration, working mainly on a project on age and income distribution and on plans for a retirement history study.

Dr.Brady was a member of the Institute of Mathematical Statistics and a former Vice president of the Ecomomic History Association.

She is surviced by a son, Michael Brady, of Oslo, Norway, and a sister, Margaret Smith, of Portland, Ore.