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First published by Russell Sage Foundation, New York, 1972 Published in Pelican Books 1973
Copyright © Russell Sage Foundation, 1972
Preface to the Pelican Edition copyright © Russell Sage Foundation, 1973
Printed in the United States of America
PUBLICATIONS OF RUSSELL SAGE FOUNDATION
Russell Sage Foundation was established in 1907 by Mrs. Russell Sage for the improvement of social and living conditions in the United States. In carrying out its purpose the Foundation con- ducts research under the direction of members of the staff or in close collaboration with other institutions, and supports programs designed to develop and demonstrate productive working relations between social scientists and other professional groups. As an integral part of its operations, the Foundation from time to time publishes books or pamphlets resulting from these activities. Publication under the imprint of the Foundation does not neces- sarily imply agreement by the Foundation, its Trustees, or its staff with the interpretations or conclusions of the authors.