CHAPTER 11
INDEX NUMBERS OF THE COST OF LIVING, BY
THE NATIONAL INDUSTRIAL CONFERENCE
BOARD
HE oldest continuous index number of the cost of
living for the United States as a whole is that of the
National Industrial Conference Board. The origin
of this number was an estimate made in June, 1918, of the
increases in the cost of living within the war period, beginning
in July, 1914. Interest in measuring changes in the cost
of living then centered in changes within a selected period
of time rather than in changes from what might have been
considered normal conditions; hence the adoption of a single
month, that of the beginning of the war, rather than an
average of several months or years.! The same requirements
conditioned the next estimate of changes in the cost of living,
and the base period was kept at July, 1914. While theoretic-
ally a single month used in this way affords a less desirable
base period than an average of a greater variety of conditions
over a longer period, the use of this particular month throws
no great irregularity into the series, owing to the fact that
the increase between the immediately preceding pre-war
year, 1913, usually accepted as normal, and July, 1914 was
probably not more than 1%.? The retail food price index
number of the United States Bureau of Labor Statistics,
based on average prices in 1913, is used in the National In-
dustrial Conference Board series as a measure of changes in
food prices. without conversion to the July, 1914, base. The
1 Tt is of interest to note that the first estimate of the United States Bureau of
Labor Statistics was made on the same basis. Itwas later changed toa year’s aver-
age. See pp. 63-65.
2 This estimate is based almost entirely on the increase in food prices. See
Monthly Labor Review, November, 1919, pp. 192-193. The Massachusetts Com-
mission on the Necessaries of Life estimated an increase in Massachusetts of 2.19,
in this period, including increases in the cost of food, clothing and shelter, Report,
1920. op. cit.. pp. 20. 118.
