Unlike most academic sociologists, Mr. Young could translate ideology into brick and mortar. Celebrated by colleagues for charm, energy and a sense of mission that harked back to Victorian reformers like Henry Mayhew, Mr. Young founded more than a dozen social-service organizations, including the Consumers' Association, whose magazine ''Which?'' rated products; the Advisory Center for Education (whose magazine ''Where?'' rated schools); and a televised ''university of the air,'' which was the model for Britain's Open University, renowned for making secondary education broadly accessible.

Michael Dunlop Young was born Aug. 9, 1915, in Manchester, England, and spent his early boyhood in Australia. His parents were artists -- his father a violinist and music critic, his mother an actress and painter -- and money was scarce. As his parents' marriage dissolved, they briefly considered giving him up for adoption; the enduring memory of fear and powerlessness from that time, he later said, inspired his lifelong campaign to help the disenfranchised.

Returning to England, he attended a series of authoritarian schools before landing, at 14, at the Dartington Hall School in Devon, a progressive institution offering a utopian, yet pragmatic, education, where it was hoped that young Michael would emerge as a highly trained fruit farmer.

He went, instead, to the London School of Economics and was called to the bar in 1939, though he never practiced law. In 1945, he became director of research for the Labor Party, where he drafted its platform, titled ''Let Us Face the Future.'' In it, Mr. Young set forth the party's mission: to build a ''free, democratic, efficient, public-spirited country with its material resources organized in the service of the British people.'' Mr. Young's work was credited with helping assure the victory of the Labor government of Prime Minister Clement Attlee over the Conservatives and their leader, Winston Churchill.

In 1951, Mr. Young left his party post to pursue a doctorate in sociology from London University, and later helped found the Institute of Community Studies, a research institution concerned with housing, poverty and family life. ''Family and Kinship in East London'' grew out of the institute's fieldwork: Mr. Young and his co-author, Peter Willmott, surveyed residents of a tight-knit working-class London community who had been resettled in a suburban ''housing estate.'' Their work described the social costs that resulted.