FINDINGS OF THE COMMITTEE 37 
We find further evidence in the study of the data grouped accord- 
ing to levels of performance. This grouping, which is explained later 
in more detail, is based on the direction of year-to-year changes in the 
rates, the plants being rated as “High Level,” or “Low Level,” as 
distinguished from the “Mean Level” of the entire group. As will be 
seen later, the “High Level” attainment implies the existence of a high 
degree of positive correlation, since this classification requires that 60% 
or more of the year-to-year rate changes shall be of the + (produc- 
tion) — (accident frequency) type. Of 330 plants, each yielding an 
experience of four years or more, 81 were in the “High Level” group. 
In their case, 60.9% of the year-to-year changes showed the desired 
association of productivity and accident frequency as against 47.3% in 
the case of the entire group. This also appeared to the Committee to 
be indicative of the existence of a correlation which is most strongly 
marked among plants which have to their credit a better-than-average 
degree of attainment in both productivity increase and accident reduc- 
tion, and may be paraphrased by the statement that the plants which 
appear to have made the greatest progress in accident prevention have 
also made the greatest progress in productivity. 
In the safety movement, the thesis that the safe factory is the 
TABLE :-E 
INCREASES IN THE RATES OF PRODUCTION ACCOMPANIED BY INCREASES IN BOTH THE 
ACCIDENT FREQUENCY AND ACCIDENT SEVERITY RATES FOR 10 INDUSTRIAL GROUPS 
WITH 72,200 EMPLOYEES 
Industrial groups 
Automobiles... 
Beehive Coke. . | S404 win] 
Fine Specialty Machines. 
Forgings..." . 
Gold, Silver and Miscella- 
neous Mining... .. 
Special Machinery . . ... 
Valves and Fittings. . .... 
Wood-working Products. 
Writing Paper, , ‘inn 
Yarn and Thread a 
Num- 
ber of 
com- 
vanies 
4 
99 
3 
4 
2,007 
3 
3 
5 
3. 
3 
Length 
of 
experi- 
ence 
in 
vears 
4 
9 
5 
3 
Q 
5 
Number 
of 
employees| 
14,427 
6,450 
5,542 
2,240 
29,718 
4,731 
3,358 
1,410 
1,996 
2,210 
Per cent 
increase 
in 
produc- 
tion 
19.5 
47.4 
17.9 
20.1 
41.4 
2.4 
16.3 
37.3 
15.3 
17.3 
Per cent 
increase 
in 
accident 
fre- 
quency 
4.4 
9.4 
48.3 
20.4 
79.2 
53.2 
22.6 
0.4 
41.0 
12.1 
Per cent 
increase 
in 
accident 
severity 
22.2 
26.8 
91.1 
53.5 
14.17 
92.5 
224.8 
123.2 
06.0 
181.0 
1 Fatality rate.