1The research reported here was supported in
large part by a grant to the senior author from the
Mershon Social Science Program at Ohio State University.
Lome Rosenblood assisted in the data analysis,
part of which was performed using facilities
provided by the Computer Center at Ohio State
University. The authors wish to thank Timothy C,
Brock, Edward E. Jones, and Thomas M, Ostrom
for their comments on an earlier draft of this report.