Bibliographical noteFunding Information:
*We are indebted to James Morgan for making the data presented herein available to us. This research was supported in part by a Faculty Research Grant and Fellowship awarded to the senior author by the University of Michigan. We are indebted to Thomas Smith and Gudmund Iversen for their comments on an earlier draft of this paper. Portions of the paper were presented at the 64th Annual Meeting of the American Sociological Association, San Francisco, 1969.