ALCOHOL AND LONGEVITY 237 
an amount might not produce much loss of efficiency 
if spread evenly over the week, and especially if it were 
drunk after the evening meal when the day’s work was 
over, but we have seen that there is a tendency to 
increase the drinking at week-ends, and consequently 
to diminish the drinking in the middle of the week. 
Excessive drinking not only causes an immediate 
reduction of manual efficiency, but it lowers the “ will 
to work ” so much that the workman stops away 
altogether for a day or even more. Though admittedly 
there is no exact evidence available, it seems probable 
that, taking industry all through, the total reduction 
in efficiency produced by the consumption of alcohol 
is something like 10 per cent. Even if it is only half 
this figure, such a reduction might mean all the 
difference between success and failure when competing 
for world markets against a country which had adopted 
prohibition.