PREFACE 



The subject of this thesis was suggested to me by my 

 former teacher, Professor David Kinley, of the Univer- 

 sity of Illinois. Credit for helpful suggestions and in- 

 spiration is due also to Col. Carroll D. Wright, formerly 

 U. S. Commissioner of Labor ; to Professor I. P. Rob- 

 erts, of Cornell University ; to the members of Profess- 



A m +~ 



or Ely's seminary in economics in the University of 

 Wisconsin, during the school-year 1902-03 ; and to the 

 members of the Publication Committee of the American 

 Economic Association. To Professor M. B. Hammond, 

 now of the Ohio State University, I am indebted not 

 only for helpful suggestions made during the two years 

 I was a student in the University of Illinois, but also 

 for a most severe yet kindly criticism of the paper after 

 I thought I had it finished. 



In the preparation of the paper I have been careful 

 to avoid trying to prove a theory, preferring rather to 

 let the data tell their own story. 



H. W. QUAINTANCE. 



University of Missouri, 

 Columbia, Mo. 



