Laws of Technological Progress University of Waterloo December 7, 2009
J. Doyne Farmer Santa Fe Institute
from: A Short History of Technology, by T.K. Derry and Trevor I. Williams (1960). p.191.
Egyptian sledge
from: Life in Ancient Egypt, by Adolf Erman, p. 476
from: Life in Ancient Egypt, by Adolf Erman, p. 464
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? 5
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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Happiness through time
from: Culture and Subjective Well-being, edited by Ed Diener and Eunkook M. Suh (2000)
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. 8
Technological change is incremental (though with punctuated equilibria)
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The heroic theory of invention
from: “The Evolution of Technology,” by George Basalla (1988).
Newcomen’s steam engine
Hero’s steam engine (200 BC).
from: “The Evolution of Technology,” by George Basalla (1988).
SHIELD BIRD CLUB W NE
THROWING STICK
CA DO LE NI A
LANCE
MUSHROOM CLUB
ST AU LIA RA
AU RA ST A LI DO LE NI
WAR PICK
A
BOOMERANG LEANGLE
CA
from: “The Evolution of Technology,” by George Basalla (1988).
W NE
W BO ADD OM ER Y AN G
There is no good classification system for technologies
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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
The five simple machines
Wheel and axle pulley
screw
wedge
lever
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?
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Wright’s law (1936)
Progress depends on learning, proxied by production experience Cost vs. cumulative production = power law
Thomas Paul Wright
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 transistors We 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 0.169
Wright 0.177
laggedWright 0.180
Moore 0.176
Goddard 0.202
p-values for pairwise comparisons: Sinclair Wright laggedWright Moore Wright 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 learning
Joint work with James McNerney, Sid Redner, and Jessika Trancik
James McNerney
Sid Redner
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. metabolism technologies enable other technologies Need to treat change as an evolutionary process Theory 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 progress i.e. forecast is better than no forecast No good theory for technological improvement
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