Key points are not available for this paper at this time.
This research was supported by National Science Foundation Grant SOC7727365. Lawrence Santi assisted with computations and analysis. The study is a response to questions raised in correspondence with David Knoke, and his suggestions concerning a previous draft of the chapter were most helpful. Philip Converse also made helpful comments. Neither of them is necessarily in agreement with this chapter's conclusions.
Otis Dudley Duncan (Thu,) studied this question.