CONTENTS 



Page 



Introduction 1 



Theory of birectilinear approach 1 



Comparison with other types of curves and methods of curve 



fitting ^ 



Return "hindcasts," 1958-67 3 



Empirical data 3 



Birectilinear regressions 4 



Computation of returns 5 



Comparison of hindcasts, published forecasts, and actual 



runs 6 



Summary 8 



Acknowledgments 8 



Literature cited 8 



