There is another statistical illusion which is independent of class
differences. A common complaint of houseowners is that the Public Health
Authorities frequently compel them to instal costly sanitary appliances
which are condemned a few years later as dangerous to health, and
forbidden under penalties. Yet these discarded mistakes are always made
in the first instance on the strength of a demonstration that their
introduction has reduced the death-rate. The explanation is simple.
Suppose a law were made that every child in the nation should be
compelled to drink a pint of brandy per month, but that the brandy
must be administered only when the child was in good health, with its
digestion and so forth working normally, and its teeth either naturally
or artificially sound. Probably the result would be an immediate and
startling reduction in child mortality, leading to further legislation
increasing the quantity of brandy to a gallon. Not until the brandy
craze had been carried to a point at which the direct harm done by
it would outweigh the incidental good, would an anti-brandy party be
listened to. That incidental good would be the substitution of attention
to the general health of children for the neglect which is now the rule
so long as the child is not actually too sick to run about and play as
usual. Even if this attention were confined to the children's teeth,
there would be an improvement which it would take a good deal of brandy
to cancel.
This imaginary case explains the actual case of the sanitary appliances
which our local sanitary authorities prescribe today and condemn
tomorrow. No sanitary contrivance which the mind of even the very worst
plumber can devize could be as disastrous as that total neglect for
long periods which gets avenged by pestilences that sweep through whole
continents, like the black death and the cholera. If it were proposed
at this time of day to discharge all the sewage of London crude and
untreated into the Thames, instead of carrying it, after elaborate
treatment, far out into the North Sea, there would be a shriek of horror
from all our experts. Yet if Cromwell had done that instead of doing
nothing, there would probably have been no Great Plague of London. When
the Local Health Authority forces every householder to have his sanitary
arrangements thought about and attended to by somebody whose special
business it is to attend to such things, then it matters not how
erroneous or even directly mischievous may be the specific measures
taken: the net result at first is sure to be an improvement. Not until
attention has been effectually substituted for neglect as the general
rule, will the statistics begin to show the merits of the particular
methods of attention adopted. And as we are far from having arrived
at this stage, being as to health legislation only at the beginning of
things, we have practically no evidence yet as to the value of methods.
Simple and obvious as this is, nobody seems as yet to discount the
effect of substituting attention for neglect in drawing conclusions from
health statistics. Everything is put to the credit of the particular
method employed, although it may quite possibly be raising the death
rate by five per thousand whilst the attention incidental to it is
reducing the death rate fifteen per thousand. The net gain of ten per
thousand is credited to the method, and made the excuse for enforcing
more of it.