I= MIGRATION AND BUSINESS CYCLES 
puted composite indices of cyclical fluctuations in economic con- 
ditions by methods substantially similar to those used in the 
computation of the index for the United States just described. In 
choosing the constituent series for these “industrial composites,” as 
we shall designate them, we have selected series which are represen- 
tative of important factors in the economic activities of the given 
country, which show at least a fair degree of homogeneity in their 
cyclical fluctuations, and lastly, which are available, with minor 
exceptions, over the entire period from 1870 to 1913. 
The five series used for the United Kingdom are: wholesale 
prices, the value of exports, the tonnage of coal and of pig iron 
produced, and the per cent of unemployment among trade union 
members. For each series the cyclical fluctuations were computed 
by finding the percentage deviations from a seven-year moving 
average, smoothed to eliminate minor irregularities and to extend 
the average at the ends of the period. The results were then ex- 
pressed in multiples of the typical or standard deviation for the 
respective series, and an unweighted arithmetic average of these 
five series was computed to obtain the composite index. Inasmuch 
as the price, export, and production series will ordinarily have 
positive values when unemployment is low and negative values 
when unemployment is high, the cycles of the unemployment series 
were reversed in sign when combining them with the other series to 
form the composite, so that, for example, in a period of large unem- 
ployment the sign of the unemployment index is negative. 
The series used for the industrial composite for Germany are 
wholesale prices, the value of exports, the production of anthracite 
coal (Steinkohlen), and the production of pig iron. The methods 
of computation were similar to those used in preparing the com- 
posite index for the United Kingdom. 
The satisfactory data available for analyzing cyclical fluctuations 
of the economic conditions in Italy are relatively scant. The only 
series used in constructing the composite are the value of imports 
and the value of exports, hence this index may appropriately be 
designated as an index of Italian foreign trade. Inasmuch as the 
great bulk of coal used in Italian industries is imported and a large 
portion of some of the more important agricultural products, such 
as wine and olive oil, are exported, the index of foreign trade is 
probably a fairly good index of economic conditions in Italy, but it 
is obviously not as reliable as the composite indices for the United 
States, the United Kingdom, and Germany. 
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