* The authors are, respectively, Professor of Economics at Allegheny College and Associate Professor of Business Administration and of Economics at the University of Pittsburgh. Mr. Robert Berman, our research assistant, made a substantial contribution to this study. We are indebted to William Beranek for helpful comments on an earlier draft. An earlier version of this paper was presented at the Annual Meetings of the American Statistical Association in Fort Collins, Colorado, August 22, 1971.
Notes
* The authors are, respectively, Professor of Economics at Allegheny College and Associate Professor of Business Administration and of Economics at the University of Pittsburgh. Mr. Robert Berman, our research assistant, made a substantial contribution to this study. We are indebted to William Beranek for helpful comments on an earlier draft. An earlier version of this paper was presented at the Annual Meetings of the American Statistical Association in Fort Collins, Colorado, August 22, 1971.