A study of the principles "of self-service, their ap- 
plication to the retail distribution of foodstuffs, and 
the results obtained through their application, neces- 
sitated a close cooperation between the Bureau of 
Markets and the operators of self-serve grocery 
stores. Almost without exception the retailers from 
whom information was requested evidenced a keen 
desire to cooperate with the bureau. 
Special acknowledgment is {me to the managing 
director of the Duffy-Powers Co., Rochester, N. Y., 
for his personal aid and his generosity in granting 
the bureau practically unlimited use of the self- 
serve grocery department of the company for in- 
vestigational and experimental purposes. 
Other stores and organizations cooperating with 
the BureauNDf Markets in this study were : Hillman's, 
Chicago, 111. ; Liberty Market, Indianapolis, Ind. ; The 
Groceteria, St. Paul, Minn. ; Piggly-Wiggly, Memphis, 
Tenn.; L. S. Ayres & Co., Indianapolis, Ind.; Acme 
Stores Co., Los Angeles, Calif.; The Emporium, San. 
Francisco, Calif.; Bay Cities Mercantile Co., Santa 
Monica, Calif. ; Groceteria Stores Co., Seattle, Wash. ; 
Gerard Grocery Co., Pomona, Calif.; U-Save Stores 
(Inc.), Cambridge, Mass.; and bureau of business re- 
search of the graduate school of business adminis- 
tration of Harvard University. 
