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.