Marion B. Anderson, 70, the founder and director of Employment Research Associates, a Michigan-based organization that released reports such as "Bombs or Bread" and "The Price at the Pentagon" that were critical of defense spending, died of melanoma Dec. 7 at her home in East Lansing, Mich.

Her work reverberated through Washington because of extensive press coverage of her reports and testimony before congressional committees. She was a small (5 feet and 103 pounds) woman who loved nothing better than confounding Pentagon officials -- like the time she burst in on a meeting of the Joint Chiefs of Staff and handed them antiwar leaflets.

Mrs. Anderson, who lived in the Washington area in the 1950s and 1960s, had been involved in consumer and public affairs since the 1950s -- as a lobbyist for a Quaker interest group, a Democratic Party volunteer and an anti-nuclear activist.

Marion Block Anderson was born in New Haven, Conn., and grew up in Scarsdale, N.Y. She was a 1954 history graduate of Oberlin College.

In Michigan, she became legislative director for the state affiliate of the Public Interest Research Group, Ralph Nader's consumer activist organization.

She founded Employment Research Associates in the late 1970s. The group, with its small staff of economists, conducted research showing that huge increases to the military's budget came at the expense of other public services and did not result in significantly greater security.

Her marriage to Dr. Werner Krebser ended in divorce.

Survivors include her husband, James R. Anderson of East Lansing; two sons from her first marriage, Richard Krebser of Battle Creek, Mich., and Tom Krebser of Winchester, Va.; a son from her second marriage, David Anderson of New York; and a sister.