laws of technological progress
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Laws of Technological Progress J. Doyne FarmerTRANSCRIPT
Laws of Technological ProgressUniversity of Waterloo
December 7, 2009
J. Doyne FarmerSanta Fe Institute
from: A Short History of Technology, by T.K. Derry and Trevor I. Williams (1960). p.191.
skier
from: Life in Ancient Egypt, by Adolf Erman, p. 476
Egyptian sledge
from: Life in Ancient Egypt, by Adolf Erman, p. 464
Egyptian scales
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Outline• Why is technology an interesting topic?• Are there laws for technological evolution
and improvement in performance?• Can they be used to make useful forecasts?
– Which methods work best?– How can we use them to plan for the future?
• What causes such laws?
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Why am I interested in technology?
• Our understanding is pre-Linneus.• Role of technology in human culture and
well-being is huge and ever-expanding. • We can measure its performance, and study
how it changes with time.• Aspect of human culture that makes progress.
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from: Culture and Subjective Well-being, edited by Ed Diener and Eunkook M. Suh (2000)
Happiness through time
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What do I mean by technology?
• Lewis Mumford’s concept of technics– gadgets, artifacts, procedures, ideas, laws– a way of doing something
• Evolution of technology is in many respects similar to that of biological organisms.– Darwin: Evolution = descent with variation and
selection.
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Technological change is incremental
(though with punctuated equilibria)
from: “The Evolution of Technology,” by George Basalla (1988).
The heroic theory of invention
Newcomen’s steam engine
Hero’s steam engine (200 BC).
from: “The Evolution of Technology,” by George Basalla (1988).
Evolution of hammer
from: “The Evolution of Technology,” by George Basalla (1988).
SHIELD
THROWING STICK
BIRD CLUB
LAN
CE
MU
SHR
OO
MC
LUB
WADDYBOOMERANG
BOOMERANGLEANGLE WAR PICK
NEW CALEDONIA
AUSTRALIA
NEW CALEDONIA
AUST-
RALIA
boomerangs
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There is no good classification system for technologies
from: “The Evolution of Technology,” by George Basalla (1988).
Classification of machines?
• Early treatises on machines– Philo of Byzantium, 200 BC.– Hero of Alexandria, 62 AD., “Mechanics”,
“Book on the raising of heavy weights”• Five simple machines known to
Archimedes– Lever, wedge, screw, wheel and axle, pulley
Wheel and axle
wedgewedge
screwscrew
leverlever
pulley
The five simple machines
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What is a machine?
• Modern science is based on the mechanistic view, but there is no good definition of a machine.
• A machine is an assembly of matter capable of selectively altering other assemblies of matter.
• The key property of a machine is its ability to implement a functional constraint.
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Are there laws for technological progress?
Wright’s law(1936)
Thomas Paul Wright
Cost vs. cumulative production = power lawProgress depends on learning, proxied by production experience
Ford’s model T
Wright’s law only works when reducing cost is main objective
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Moore’s law(1965)
Originally a statement about density of transistorsWe will use to refer to the hypothesis that technological
performance improves exponentially with time
Gordon Moore
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Compatibility of wright and Moore(Sahal, 1987)
If production expands exponentially and costs drop exponentially, Wright’s law will hold.
Diversity of performance ratios
Performance curves for the EU 1980-1995 (IEA, 2000)
Progress ratios 108 cases, 22 field studies, electronics, machine tools, system components for electronic data processing, papermaking, aircraft, steel, apparel, and automobiles(Dutton and Thomas, 1984)
Alternative hypotheses
Goddard: Economy of scale (this year’s production is all that matters)
Sinclair, Klepper and Cohen (SKC) Both economy of scale (this year’s production) and learning (cumulative production) matter.
Nordhaus: Both exponential in time and power law in cumulative production.
Is technological progress
predictable?Joint work with Bela Nagy and Jessika Trancik
Testing for predictability through hindcasting
Pretend to be at a given time in the past
Use given method to forecast each future year
Repeat for all past dates
Score methods based on forecasting errors
Error analysis
Alpha:
Sinclair Wright laggedWright Moore Goddard 0.169 0.177 0.180 0.176 0.202
p-values for pairwise comparisons: Sinclair Wright laggedWright MooreWright 0.239 laggedWright 0.135 0.750 Moore 0.328 0.842 0.604 Goddard 0.000 0.003 0.009 0.002
Economic interpretation
Economy of scale alone is not a good predictor of cost.
Cumulative production is a good predictor.
It is possible to make useful forecasts of technological performance.
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Model of learningJoint work with James McNerney, Sid Redner, and Jessika Trancik
Sid RednerJames McNerney
Power law of practice
Improvement with practice in time to add two numbers(Blackburn, 1936)
Auerswald et al. Production recipe
Production costs are additive
Each operation is affected by d operations.
Innovation proceeds through a series of trials in which d operations omega_i are altered.
Design structure matrix for automobile brake system
Algorithm
Pick a component i
Randomly change its cost and all the costs of the d components that it affects.
If the total cost decreases, accept the change.
Constant out-degree
variable out-degree
Predictions of model
Rate of improvement depends on interconnectness of components, not on total number.
Variable interconnectness can cause punctuated equilibria in performance curve.
Better theory?Need to think in terms of a network of diverse technologies
like an autocatalytic set, e.g. metabolismtechnologies enable other technologies
Need to treat change as an evolutionary processTheory should be able to say why some technologies evolve faster than others
Summary
Very little is known about evolution of technology
not even a Linnean classification scheme
Technologies make predicable progressi.e. forecast is better than no forecast
No good theory for technological improvement
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