PREDICTIONS – 10 Years Later - Santa Fe Institute

5. GOOD GUYS AND BAD GUYS COMPETE THE SAME WAY
Unknown to them, the men at the meeting had all the elements necessary
to make a fairly accurate prediction about one of the diseases that
concerned them, diphtheria, but emotions and traditional thinking
blocked a more revealing look into the future. The declining jagged line
in Figure 5.3 shows the percentage of all deaths attributed to diphtheria
in the United States. The data come from the Statistical Abstract of the
United States. 4
The years centered around World War I show a wavy structure. The
nine-year average is designated with a big dot and falls right on the S-
curve fitted to the data points. During the early war years diphtheria
claims a particularly low share, while in the years immediately after the
war its role becomes excessively important. The situation offers itself to
a variety of explanations. Heavy loss of life in combat during the war
could result in a reduced share of deaths for the disease. The peak
claimed by diphtheria right after the war could be attributed to warrelated
consequences, such as large numbers of wounded and insufficient
supplies and medical care, conditions that may have favored
diphtheria more than other diseases for some reason. However, the fact
that peak and valley compensate each other rather precisely is evidence
for an underlying stability and supports the argument that a concerned
population shows resistance to diseases while in danger (that is, World
War I) but becomes vulnerable when the danger subsides.
The fit in Figure 5.3 is based only on the data before 1933. The dotted
line extended beyond 1933 is the extrapolation of the mathematical
function determined from the historical window 1900–1933. I truncated
history in 1933 because the antidiphtheric vaccine was officially introduced
on a large scale that year. In a country like the United States, with
excellent means of communication and an efficient medical system, one
would expect that once a vaccine becomes available for a bacterial disease,
there will be no more victims.
Surprisingly, the historical data after 1933 coincide with the extrapolation
of the fitted curve determined from the data before 1933. It
means the disease continued to decline according to a “prescription”
established before the vaccine. If anything, the data points seem to
fluctuate less in more recent years, making the agreement between the
115