THEORY OF PRODUCTIVE EFFICIENCY 193 
standards of living. These methods are not secret. They 
are open to the world. But they are rooted not alone in 
technology, which can be adopted by all intelligent people; 
they are rooted in social conceptions which penetrate far 
deeper and which not only promise greatly for the future in 
our standards of living at home, but, of more pertinent inter- 
est on this occasion, provide the basic assurance of our con- 
tinuing growth in foreign trade, both exports and imports. 
These are the fundamental forces which promise for us our 
share of the world’s increasing demands even of competitive 
zoods—if we keep them in motion. 
In this connection extended investigations and analyses 
have been made by both the Department of Commerce and 
the Bureau of Labor Statistics of the Department of 
Labor. The following table, which epitomizes the develop- 
ment of productivity from the year 1919 to 1925, both for 
‘ndustry as a whole as well as by individual workers, was 
prepared by the Department of Commerce: 
INDEX OF INCREASED PRODUCTIVIT: 
MANUFACTURING INDUSTRIES, 1925 
(1919 = 100) 
Physical Number Production 
Volume of of Primary per 
Production Persons Horsepower Person 
Vehicles for land transporta- 
tion .. - 
RubBBE wuprnvnssnmminnurises 
Metals and metal products 
other than iron and steel... 
Stone, clay and glass......... 
Tobacco manufactures ....... 
Chemicals and allied products. 
Food and kindred products... 
Paper and printing. ... . 
[ron and steel and nroduct: 
Lumber ....... 
Textiles and product: 
Leather, and its = 
tures ...... 
Ship and boat buiic 
All industries . 
13.5 
IRE 014 
24.8 
1218 
103.1 
51.9 
1407