52 BULLETIN - 1300, U. S. DEPARTMENT OF AGRICULTURE 
obtained by the assumption of paths of influence from the preceding 
fall corn crop and the breeding of the current year (spring and fall) 
with coefficients of +0.65 and +0.35, respectively. There is 61 per 
cent determination by these factors. 
In order to fit the correlations involving summer slaughter it seems 
necessary that the latter be represented as influenced by the breeding 
of the current and three preceding years and the current and two pre- 
ceding corn crops. The preceding corn crop is represented as having 
the most important direct effect ( + 0.55). The effect of crop on 
slaughter through the mediation of its stimulating effect on breeding 
is, of course, excluded from the effect measured by this coefficient. A 
direct effect of crop on slaughter of a given season can be due only to 
a redistribution oi slaughter in time or place. Whatever increase 
there is in one season in the wholesale pack must be at the expense 
of the preceding or following seasons or of the country slaughter. In 
the present case there seems to be a concentration of slaughter in the 
summer following a big crop, due largely to holding back during the 
fall and winter preceding this summer and to a less extent from an 
advance from the slaughter of the winter following. The holding 
back from the preceding winter is represented as in part handed on 
from the preceding fall ( — 0.25), and the advance slaughter from the 
following winter is represented as wholly balanced by an advance 
from the following summer ( — 0.10) . The reasons for the concentra- 
tion of slaughter in the summer following a big crop, and the reverse 
after a small crop, have been discussed. 
Winter slaughter is represented as affected most by the breeding 
one to two years before ( + 0.85). The breeding for the two years 
before, however, must also be assumed to have effects ( + 0.35, + 0.15) . 
As previously suggested, it is not the actual hogs resulting from the 
breeding of these earlier years which swell the winter slaughter in 
question, but the effect of a surplus of hogs in increasing the age of 
slaughter. The holding back in one year tends to cause a surplus in 
the next, and a repetition of the holding back. 
Summer pack is not affected to so great an extent as winter pack 
by the breeding of any one year. It seems, however, to be affected 
almost equally by the three preceding years. The marked effect 
of the third preceding year ( + 0.35) was not expected but seems to be 
a necessary assumption in accounting for the correlations. The 
breeding of the current year naturally has a slight negative influence 
on the summer pack ( — 0.10). 
The foregoing factors determine summer pack 74 per cent, and win- 
ter pack 79 per cent. 
PORK PRODUCTION AND TOTAL WESTERN PACK 
Summer and winter pork productions are simply the products of the 
pack and weight for the corresponding seasons. In round numbers 
the correlations involving summer pork production result from path 
coefficients of value, +0.95 from summer pack and +0.20 from sum- 
mer weight. The corresponding path coefficients in the case of winter 
pork are +0.95 and +0.25, respectively. These coefficients give an 
apparent 90 per cent determination in the case of summer pork and 
87 per cent in the case of winter pork. 
