PREDICTIONS – 10 Years Later - Santa Fe Institute

9. REACHING THE CEILING EVERYWHERE
like automobile populations and highway construction, are slowing
down reaching a ceiling. The group at IIASA (Marchetti, Nakicenovic,
and Grubler) has indulged in fitting logistic functions on growth processes
by the hundreds for over a decade. The cases span the last three
hundred years and predominately concern the construction of infrastructures
and the substitution and diffusion of technologies. When Debecker
and I came across Grubler’s book The Rise and Fall of Infrastructures,
which contains many of the IIASA results, we decided to produce one
drawing on which all these curves were superimposed. The original fits
had been reported as straight lines on logistic scales. We transformed
them back into S-shapes. In Figure 9.2, we included some of the curves
which we had determined ourselves concerning computer innovation,
subway inaugurations, and airways.
There are more than fifty growth processes shown, each with its ceiling
normalized to 100 percent. In the table below, The Timing of
Technological Growth Curves, the name of each technology is listed in
chronological order along a line at 50 percent. As we expected, the
curves coalesced into clusters, merging together as they approach the
ceiling that indicates saturation. The left-most three curves, in the late
eighteenth and early nineteenth centuries, represent canal construction.
The next group includes primarily diffusion of steamships and railway
networks; the fast-rising ones to their right are automobile substitutions
for horses. In the twentieth-century cluster at the far right, road
construction and replacement of steam locomotives are seen to grow
slowly, followed by automobile populations, which grow more quickly.
Among the recent curves are some that describe innovation in the computer
industry.
We then compared these natural-growth curves to the fifty-six-year
cycle of energy consumption, which coincides with the economic cycle.
We observed a remarkable correlation between the time these growth
curves approach their ceiling and the valleys of the economic cycle. It
thus becomes evident that boom or prosperity, which occurs during a
peak of the cycle, coincides with technological growth while recession
coincides with the saturation of these technologies. The industries built
around these technologies follow the same curves and also saturate at
the same time.
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