COST OF LIVING INDEXES COMPARED 127 
naires or agents are used in a cost of living survey is largely 
a practical question. To the extent that standardization is 
possible, questionnaires may well be used; where judgment 
or discretion is involved the choice seems to lie between 
trusting to the decision of a special agent or of the mer- 
chant. 
SUMMARY 
The differences between changes in the retail price level 
in the United States as shown by the index numbers of the 
cost of living computed by the National Industrial Con- 
ference Board and by the United States Bureau of Labor 
Statistics, respectively, tend to disappear when both are re- 
duced to the same basis. The most important reasons for 
the existing differences are that the National Industrial 
Conference Board series is based on a pre-war budget and 
pre-war consumption and reflects, as well as may be possible 
in a single average, conditions in the country as a whole, 
whereas the Bureau of Labor Statistics series is based on a 
war-time budget and war-time consumption and is more ex- 
clusively an urban index, since a far larger proportion of the 
total localities covered are the largest cities in the country. 
Another important reason for the difference between the 
two series is in the choice of the samples used to measure the 
change in cost of the major items making up the total cost 
of living. In all but the food group, which is identical in 
both series, the samples are quite different. While the trend 
of costs for clothing and for sundries is much the same, the 
percentages of change themselves differ throughout the 
series. The rent and fuel and light curves, while not so 
uniform in their trend, are not radically different. These 
circumstances lend a considerable degree of confidence to 
both series, and strengthen the belief that each is substan- 
tially correct. What samples are to be chosen or how prices 
of them are to be collected and combined are largely mat- 
ters of judgment and expediency. The outstanding fact is 
that an index number of the retail price level can be con- 
structed with a fair degree of accuracy and may be used with 
a fair degree of confidence. Which series is adopted depends, 
of course, on the purposes which are to be served. 
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