Is Technological Progress a Thing of the Past?
Joel Mokyr
Departments of Economics and History
Northwestern University
Berglas School of Economics
Tel Aviv University
Milan Expo Meeting, Sept. 2015
1
Economics, sometimes known for being “the dismal
science” has always had its share of alarmist and scary
predictions of stagnation and economic decline.
Among the many scenarios suggested in the past:
• Overpopulation and Malthusian disasters
• Population aging and fertility decline
• Resource exhaustion
• The welfare state is unsustainable
• Structural lack of aggregate demand (secular stagnation)
• Environmental disasters such as climate change
Milan Expo Meeting, Sept. 2015
2
Most recently the question that has been raised is: can we
keep up the technological momentum that has so
dramatically changed our lives since 1850 or so?
Milan Expo Meeting, Sept. 2015
3
A new wave of techno-pessimism is upon us:
The new technopessimist interpretation (for instance Robert
Gordon) says that the low-hanging fruits of invention have all
been picked.
Future inventions, we are told, will not have nearly as radical
an effect as before.
For that reason, innovation will not be powerful enough to
counter other economic “headwinds” and annual GDP growth
will slow down to a trickle.
Milan Expo Meeting, Sept. 2015
4
Innovation pessimism
Has the ideas machine broken down?
Milan Expo Meeting, Sept. 2015
5
Gordon is not alone:
Many feel disappointed. Peter Thiel (of Paypal fame) has
famously remarked “we wanted flying cars, instead we got
140 characters.”
To which I would reply: wait till you need a hip replacement,
buddy.
Milan Expo Meeting, Sept. 2015
6
Is the world running out of ideas?
Perhaps the low-hanging fruits that have changed our lives
have been picked: running water, chlorination, electricity, air
conditioning, antibiotics etc?
But science and technology’s main function in history is to
make taller and taller ladders to get to the higher-hanging
fruits (and to plant new and maybe improved trees).
Moreover, the old trees will keep sprouting new fruits, if only
we give them proper care.
Milan Expo Meeting, Sept. 2015
7
Of course, some other people are hyperoptimists
They argue that the rapid improvements in computation
and artificial intelligence (AI) have the potential to increase
its productivity and breadth to the extent that human labor
and intelligence will become increasingly superfluous.
This is what is known as “singularity” associated with such
futurist as Ray Kurzweil in which machines not only
replicate themselves but actually are capable of what is
known as recursive self-improvement.
Milan Expo Meeting, Sept. 2015
8
Ray Kurzweil, computer scientist,
inventor and futurist
Milan Expo Meeting, Sept. 2015
9
“The productivity of computers and software has grown at
phenomenal rates for more than a half-century, and rapid
growth has continued up to the present. Developments in
machine learning and artificial intelligence are taking on an
increasing number of human tasks, moving from
calculations to search to speech recognition, psychotherapy, and robotic activities on the road and battlefield. At
the present growth of computational capabilities, some
have argued, information technologies will have the skills
and intelligence of the human brain itself” (Nordhaus,
2015).
Milan Expo Meeting, Sept. 2015
10
Quite a few people think that this is a dystopian prediction
and could be even worse than secular stagnation.
But economists of course know that it is not at all clear that
singularity is likely: computer intelligence and human
intelligence are good at quite different things and may be
more complements than substitutes, that is, they will work
together rather than replace each other.
My view is that computers, rather than becoming our masters,
will help us understand and dominate nature better.
[I will come back to this point].
Milan Expo Meeting, Sept. 2015
11
So the Big Question is:
Quo Vadis, Technology
What can an economic historian bring to this
discussion?
Here is the take-home line:
If the patterns of the past hold (a big if), there is
good reason to expect the rate of technological
change to accelerate over the next decades,
although it would be foolhardy to be more
specific than that (and even more to try to predict
the rate of productivity growth or whether we are
facing a Kurzweilian singularity).
Milan Expo Meeting, Sept. 2015
12
At least to give us some perspective to appreciate
“Amara’s Law”
“We tend to overestimate the effect of a
new technology in the short run
and underestimate the effect in the long run.”
Roy Amara,
Past president of
The Institute for the Future.
Milan Expo Meeting, Sept. 2015
13
Can growth continue?
The world is running into “headwinds” that are supposed to slow
the industrial economies down to a trickle. A few of those
seem at first glance to be ineluctable.
•
Population ageing
•
Declining employment and L-force participation.
•
National indebtedness
•
Education running into diminishing returns.
•
Environmental problems and climate change.
[note: many of those things are only “bad” if your objective is to
maximize GDP as currently
defined]
Milan Expo Meeting, Sept. 2015
14
But against that, I argue:
The “tailwind” from technology is likely to be so powerful that,
like a tornado, it will overcome all “headwinds” from other
factors.
Can I be sure? No.
Can we learn anything from history here?
The best I can do is point to four factors that I think made a
difference in the past, and then argue that they are much
stronger today than ever before.
Milan Expo Meeting, Sept. 2015
15
Four factors that mattered in the past:
•Pluralism and Diversity
•Artificial Revelation
•Access costs
•Good incentives for intellectual innovation and a well-defined agenda.
So my plan is: show their historical importance, and then argue that
they hold for today’s world a fortiori.
Milan Expo Meeting, Sept. 2015
16
Factor one: pluralism and competition
Milan Expo Meeting, Sept. 2015
17
Why do Diversity and Pluralism matter?
There are two ways to think about it.
One is the evolutionary notion that creativity is the result
of diversity, because progress occurs through a
process of selection, and as we have known ever
since Darwin, the more items there are to select from
on the “cultural menu,” the more likely it is that “fitter”
varieties will occur.
The other is the economic model of competition that says
that in a world in which many entities compete hard,
progress is more likely to occur because no competitor
wants to “fall behind” (and those who do, drop out).
Milan Expo Meeting, Sept. 2015
18
These two stories are not mutually exclusive and in fact
both shed some light on why economic growth and
technological progress started in the Western World
around 1750 with the Industrial Revolution.
This is the topic of my new book, A Culture of Growth:
Origins of the Modern Economy (Princeton: Princeton
University Press, forthcoming, 2016).
Milan Expo Meeting, Sept. 2015
19
According to that story, the political fragmentation
and the religious and cultural pluralism of Europe
was a key to its success.
This was, interestingly enough, fully realized by
philosophers of the Age of Enlightenment
Milan Expo Meeting, Sept. 2015
20
• Europe is now divided into twelve powerful, though unequal,
kingdoms, three respectable commonwealths, and a variety of
smaller, though independent, states: the chances of royal and
ministerial talents are multiplied, at least, with the number of its
rulers . . . The abuses of tyranny are restrained by the mutual
influence of fear and shame; republics have acquired order and
stability; monarchies have imbibed the principles of freedom, or, at
least, of moderation; and some sense of honour and justice is
introduced into the most defective constitutions by the general
manners of the times. In peace, the progress of knowledge and
industry is accelerated by the emulation of so many active rivals; in
war, the European forces are exercised by temperate and
undecisive contests." (Gibbon, 1789, V.3, p.636)
Zurich conference, Nov. 2014
21
Here on the same topic is the greatest of all Enlightenment writers:
Milan Expo Meeting, Sept. 2015
22
“Nothing is more favorable to the rise of politeness and
learning than a number of neighbouring and independent
states, connected together by commerce and policy. The
emulation, which naturally arises among those... is an
obvious source of improvement. But which I would chiefly
insist on is the stop [constraint] which such limited
territories give both to power and authority... The divisions
into small states are favourable to learning, by stopping the
progress of authority as well as that of power.
David Hume (1742)
Milan Expo Meeting, Sept. 2015
23
Modern economics agrees:
We know that the competitive model is a good approximation
for the behavior of political entities in the seventeenth
and eighteenth centuries the time, which encouraged
and even supported scientific and technological
advances, not out of altruism but to keep ahead (or at
least to keep up).
Moreover, fierce competition took place not only between
nations but also within them, for example between
different religious groups or between cities and regions.
Milan Expo Meeting, Sept. 2015
24
The evolutionary model suggests the same:
In Europe of the sixteenth and seventeenth century a lot of
“new cultural varieties” began to emerge and increased
the size of the “menu” from which people could choose.
Two examples: in medicine, the old “humoral theory” inherited
from the Greeks and Arabs of disease now had to
compete with the “iatrochemical” school founded by the
great Swiss physician Paracelsus.
In physics, Cartesianism competed with Newtonianism in the
late seventeenth and eighteenth centuries, and the
“atomic theory” (known as corpuscularianism) competed
with “vitalism” and both competed with Aristotelianism.
Milan Expo Meeting, Sept. 2015
25
What made this market so competitive
is well-understood:
•
•
•
The invention of the printing press, the growth of
epistolary networks, and the growth and proliferation of
universities and non-academic institutions of learning
such as the Accademia dei Lincei and the Académie
Royale.
These were happening in a world in which courts and
universities of many kingdoms, cities and principalities
were competing to attract the best and the brightest.
But the scholars and intellectuals also competed with
one another for the best patronage positions.
Milan Expo Meeting, Sept. 2015
26
As the Talmud says:
“The jealousy of learned men
will increase wisdom”
Milan Expo Meeting, Sept. 2015
27
What emerged from all this was a new world.
It led to breakthroughs in science and technology, and
eventually to the Industrial Revolution and modern
economic growth which were driven by them.
Milan Expo Meeting, Sept. 2015
28
So what does this model predict for today?
The world is more pluralistic and competitive than ever.
Globalization does NOT imply that competition
between 5-6 major blocks is not as intense as it was in
the seventeenth century (but it is to be hoped that it
will not end the same way in a series of destructive
wars).
All participants realize that unless they keep up with bestpractice science and technology, they will fall
hopelessly behind in the global competition.
Milan Expo Meeting, Sept. 2015
29
One obvious reason is that globalization is far from
creating a homogeneous world.
Different cultures create different forms of innovation.
Globalization means that all players are exposed to and
have access to these options subsequently.
So we have American genetic modification, German chemistry,
Israeli software, and Chinese advances in acupuncture
and moxibustion, among many others.
But today’s world is different in one respect: if an invention is
made somewhere, it is made everywhere. Diffusion is
Milan Expo Meeting, Sept. 2015
30
immediate.
Factor 2: Artificial Revelation:
Milan Expo Meeting, Sept. 2015
31
Artificial Revelation
• What drives scientific advances at any time? They are
driven by many factors, but one of the most important is
the tools and instruments available to scientists.
• Thus technological progress stimulates and helps
scientific advances no less than the reverse.
Milan Expo Meeting, Sept. 2015
32
Why is this so important?
Simply, because our senses and brains are too limited for
much of nature, which operates at scale, frequencies,
distances, and bandwidths that we cannot observe.
We only observe them through “artificial revelation.”
Moreover, many important phenomena are also “too
complex to compute” by hand.
So we need tools.
Milan Expo Meeting, Sept. 2015
33
This was certainly true for the scientific revolution in the
17th Century.
The best-known examples are of course “the great trio” of the
telescope, the microscope, and the barometer, all developed
during the early seventeenth-century. These three instruments
played a big role in the Scientific Revolution. But there are
many others.
Let me give you a few lesser-known examples from the era
before and during the Industrial Revolution to drive the point
home.
Milan Expo Meeting, Sept. 2015
34
Boyle’s famous air pump
Robert Boyle’s famous air pump,
built in the late 1650’s, which
showed once and for all that
contra Aristotle, nature did not
abhor a vacuum, and thus paved
the road for atmospheric (steam)
engines.
Milan Expo Meeting, Sept. 2015
35
Volta’s “pile” (1800)
Volta’s battery provided chemists
with a new tool, electrolysis,
pioneered by Humphry Davy. He
and other chemists were able to
isolate element after element,
and fill in much of the detail in the
maps whose rough contours had
been sketched by Lavoisier and
Dalton.
36
And in medicine:
Joseph J. Lister (father of the famous
surgeon), inventor of the achromatic
microscope that minimized both
chromatic and spherical aberration.
This made it possible eventually for
Pasteur, Koch and others to demonstrate that infectious diseases were
directly linked to identifiable
microorganisms.
Milan Expo Meeting, Sept. 2015
37
Better tools make for better science
This, to, is true a fortiori in our age.
Science’s toolkit has grown enormously in the past decades.
This expansion cannot but lead to rapid applications, in fields
that are at times obvious and immediate but often unexpected.
Examples are easy to come by.
Start with telescopy, in honor of Galileo:
Milan Expo Meeting, Sept. 2015
38
Galileo never had this:
Artist’s impression
of the European
Extremely Large
Telescope
deploying lasers for
adaptive optics
Future of Work
39
Here is what is can do:
OECD, Paris Sept.2014
40
Adaptive optics
1.
2.
3.
These are two images of the planet Uranus, one using
an ordinary telescope, the other one in which the
blurring caused by atmospheric distortions are
corrected through adaptive optics.
Adaptive optics technology sharpens images by
changing the shape of telescope mirrors up to 1,000
times per second.
It is believed to have more potential than Hubble’s
telescope (and is a lot less expensive).
OECD, Paris Sept.2014
41
Neither did Pasteur have this:
Betzig-Hell type of
stimulated
emission depletion
(STED)
microscope
Future of Work
42
Another example how new technology
helps science:
Automatic gene
sequencing machines,
first developed in 1986
by Dr. Leroy Hood’s
laboratory at CalTech,
critical in sequencing
of genome.
OECD, Paris Sept.2014
43
And perhaps the most revolutionary:
OECD, Paris Sept.2014
44
And Now: CRISPR
Jennifer Doudna
Northwestern Central Bankers
meeting, Sept. 2015
Meeting,
45
1.
2.
3.
CRISPR basically works a bit like the “find-andreplace” function in word-processing. It may, within a
generation, rid us of all 6,000 genetic diseases, from
common one like Tai-Sachs and sickle-cell anemia, to
rare diseases such as San Filippo syndrome.
But it can be used to knock out genes or sets of genes
quickly and cheaply, and thus allow scientists to study
disease that depend on sets of genes such as
diabetes and autism.
Its capabilities in “redesigning organisms” maybe
unlimited.
Milan Expo Meeting, Sept. 2015
46
Even more impressive: it allows scientists to manipulate germ-line cells,
and thus have the new genetic configuration passed on in perpetuity.
This has raised a lot of debate among bio-ethicists. A concern that
scientists could create “supermen” is only one of those.
But even we ban this technique in humans, we could apply it to all other
creatures and create plants and animals according to the specifications
we want --- including for instance their ability to withstand the vicissitudes
of climate change and growing water scarcity.
Northwestern Central Bankers
meeting, Sept. 2015
Meeting,
47
Finally, of course, the computer
It is hard to think of a single field of research that has
not been transformed by computers.
The real question often seems to be: what did we ever
do before it?
My interest here is not in what the digital revolution
does for productivity directly, but rather indirectly
through its effect on science.
OECD, Paris Sept.2014
48
Computers allow research hitherto impossible
In Chemistry: Multiscale Models of Complex Chemical
Systems, which allows the solution of the complex
equations that govern the properties of quantum
chemistry.
In Physics: allow the simulation of complex differential
equations (Navier-Stokes) that are known to govern
turbulence but cannot be solved.
In Material science: We now can simulate the equations
that define the properties of materials using highthroughput super-computers to experiment with
materials having pre-specified properties in silico.
OECD, Paris Sept.2014
49
The new science then “feeds back” into technology, at
times with enormous power.
In this way, technology (instruments) and science mutually
reinforce one another in a positive feedback loop.
Or, another way to look at it: technology pulls itself up by its
bootstraps through the intermediation of science.
OECD, Paris Sept.2014
50
Why does this matter?
Much of the discussion about the coming of the future of
the digital revolution is about its direct impact on
consumption and production:
Will we have robots making us coffee, driving trucks, pick
our tomatoes and babysit our infants? Will Artificial
Intelligence teach our students and program our lives??
Milan Expo Meeting, Sept. 2015
51
But that forgets the important indirect effect:
IT  Science  other technologies
Milan Expo Meeting, Sept. 2015
52
Here is an example (from French expo 2015 pavilion)
The use of digital technology to assist evolutionary
selection: high-throughput phenotyping platforms, equipped
with robots and cameras, which enable them to detect plant
genes that are better adapted to human and environment
needs. These platforms can characterize and sort 1000’s of
individual plants through automated means and on a daily
basis.
This maybe a partial substitute for genetic modification,
since it relies only on “natural” mutations.
Milan Expo Meeting, Sept. 2015
53
Factor 3: Access Costs:
Milan Expo Meeting, Sept. 2015
54
Some very important pieces of knowledge that “are known”
to society are only possessed by few smart individuals.
And hence, access by others who do not have this
knowledge but need it is important. Such access is costly.
Milan Expo Meeting, Sept. 2015
55
Why is access so crucial to sustained
technological dynamism?
•
•
•
•
Part of it that more and more invention requires access to
the best science available in material science, biochemistry,
combustion, etc.
Even if science is not directly very useful in guiding an
inventor, it is still true that Fortune favors the prepared mind.
But it is also true that technology advances by “ideas having
sex” as one writer famously described it. So if you have one
idea, you need access to “a partner”.
Finally, inventors have to know what is already known, so
that they don’t reinvent more wheels than is unavoidable.
Milan Expo Meeting, Sept. 2015
56
This does not matter as long as users who need this
knowledge have access to it.
• But access can be costly. What determines access costs?
• Among many factors, clearly the technology of storing
codified information and searching through it figure highly.
• In the past, the most important advances in informationstorage and search-engine technology were the invention of
writing, paper and the printing press.
Milan Expo Meeting, Sept. 2015
57
But knowledge needs to be organized if access is
to be fast and cheap and searches are to be
efficient.
The Age of Enlightenment that preceded the
Industrial Revolution blazed new trails in access
capability in technology and in science, both for
codified and tacit knowledge.
Milan Expo Meeting, Sept. 2015
58
The eighteenth century version of the search engine was
the encyclopedia. Alphabetized encyclopedias and
indices to technical books were the Googles of their age.
And indeed, the paradigmatic enlightenment document is
Diderot’s Grande Encyclopédie.
Milan Expo Meeting, Sept. 2015
59
Pinmaking essay in Diderot’s encyclopedia
Milan Expo Meeting, Sept. 2015
60
What about today?
If ICT has done anything, it has reduced access costs.
We no longer deal with “data” ̶ we have “meta-data,”
amazing quantities of information that can only be accessed
with sophisticated searchware.
We can search for nanoscopic needles in haystacks the size
of Montana.
This is certainly not without its drawbacks, as both spies and
advertisers know more and more about us.
But it has enormous implications for further scientific
research and technological advances.
Milan Expo Meeting, Sept. 2015
61
Anyone engaged in research can access vast banks of
knowledge and data. Cloud technology is just getting started.
We measure storage now not in petabytes but Zettabytes (a
million petabytes) and Yottabytes (1000 Zettabytes)
(WHO makes up those terms? --- there is also “Brontobytes”).
And they move around the planet in seconds. As Matt Ridley
has remarked, “The cross-fertilization of ideas between, say,
Asia and Europe, that once took years, decades, or centuries,
can now happen in minutes.”
.
Milan Expo Meeting, Sept. 2015
62
Public databases are a huge step forward in codified
knowledge
All these databases (think Pubmed) are accessible free of
charge, with no physical effort, at the click of a mouse.
Louis Pasteur never had it so good.
But what is true for medical science is true across the
board, in material science, astrophysics, molecular plant
genetics, and economic history. “Big-data” is changing
research in every field.
Milan Expo Meeting, Sept. 2015
63
Factor 4: Incentives
Milan Expo Meeting, Sept. 2015
64
Economists love incentives. But in the generation of
science, especially, they are problematic, since knowledge
cannot be “owned” or “sold” the way other assets are
owned and sold.
Europe between 1500-1700 found a solution: great
scientists acquired reputations among their peers, and
these reputations provided them with “patronage” positions.
Galileo’s position at the court of the Grand-duke of
Florence is the most famous example.
Milan Expo Meeting, Sept. 2015
65
Following the publication of his Siderius Nuncius he was
appointed "Chief Mathematician of the University of Pisa
and Philosopher and Mathematician to the Grand Duke" of
Tuscany. The appointment was for life.
It was a very cushy patronage job. But many other
distinguished scientists were given similar arrangements.
This created incentives that worked: discover something,
get others to notice, become famous, and you’re set
(almost) for life.
Milan Expo Meeting, Sept. 2015
66
These rules still set the stage by which the game of
creating science is being played.
They are not perfect, but probably the best we can do. And
they worked well in the past.
What about today?
Northwestern Central Bankers
meeting, Sept. 2015
Meeting,
67
In our age we richly reward and honor successful
inventors and scientists.
Although most innovators capture only a minute portion of
the “social surplus” they create, we tend to respect and
reward them. And they still prefer (mostly) being famous to
being rich.
And patents, despite everything that is wrong with them (a
lot) still constitute a strong ex ante incentive for innovators.
But we also deploy other means: economic security through
tenured jobs, first-mover advantage, prizes.
These incentives have worked well for centuries.
68
Northwestern Central Bankers
Meeting, Sept. 2015
Except that today they work better: globalization creates
global superstars.
A Nobel prize means a lot more than some Swedish kroner
and dinner with the King. It means global celebrity status.
Milan Expo Meeting, Sept. 2015
69
One final thought:
• Science and Technology advance most rapidly when the
world poses them with well-defined and urgent problems
that need a solution (and those who solve it will be wellrewarded) and that are within the capabilities of that
society (unlike some advances that are at first “a solution
looking for a problem.”)
• It involves realizing that solving them will enhance social
welfare significantly. Rosenberg’s idea of “focusing
devices.”
• In other words, it helps to have a clear-cut “agenda.”
70
Northwestern Central Bankers
Meeting, Sept. 2015
The eighteenth-century Industrial Revolution did exactly
that. Britain faced a number of well-defined problems:
1.
2.
3.
4.
5.
How to pump water out of coalmines.
How to spin high quality cotton yarn inexpensively.
How to turn pig iron into wrought iron.
How to fight smallpox.
How to solve the “longitude at sea problem.”
Northwestern Central Bankers
meeting, Sept. 2015
Meeting,
71
Of course, only the problems that were in their reach were
solved. Eighteenth-century engineers could not build
airplanes or submarines, tame and harness electricity, and
even cheap steel eluded them for a long time.
The twentieth century did the same for a host of problems,
from the Haber-Bosch nitrogen-fixing process (1912) to
Project Manhattan to polio vaccines
72
Northwestern Central Bankers
Meeting, Sept. 2015
Similarly, in our own age:
many well-defined problems
1.
2.
3.
4.
5.
73
Global warming and climate change.
Ocean acidification (global warming’s ‘evil twin’)
Desertification and water scarcity.
Multidrug resistance to antibiotics.
Energy storage and transmission.
Northwestern Central Bankers
Meeting, Sept. 2015
6.
7.
8.
9.
10.
Digitally-driven mass-customization
Fish and seafood depletion.
Growing obesity.
Mental deterioration with age.
Information overload.
Northwestern Central Bankers
meeting, Sept. 2015
Meeting,
74
• Both the supply and the demand are there. We have the
tools to solve these problems, and the need.
• Yet, institutional and political factors may get in the way
in many places and slow down or block advances that
are technically possible.
• However, the good news about globalization is that if
problems get solved somewhere, they are solved
everywhere.
75
Northwestern Central Bankers
Meeting, Sept. 2015
Is this an unqualified rosy scenario?
Not necessarily.
Institutions and politics have not advanced at the same rate
as science and technology since 1750.
And hence there may be an imbalance between our
technological and our political capabilities.
Milan Expo Meeting, Sept. 2015
76
As Freud said with masterly understatement in his The
Future of an Illusion, “While mankind has made continual
advances in its control over nature and may be expected to
make still greater ones, it is not possible to establish with
certainty that a similar advance has been made in the
management of human affairs.”
Milan Expo Meeting, Sept. 2015
77
To sum up:
•We are not like the late Roman Empire or Qing China, about
to languish into an age of decline to be followed possibly by
chaos and barbarism.
•Technological progress is still remote from reaching a ceiling
or even diminishing returns (and may never do so).
•Economic growth, in an economically meaningful way (if not
necessarily in a traditional NI accounting way) will continue.
•Secular stagnation: Seems unlikely to be the problem.
Northwestern Central Bankers
meeting, Sept. 2015
Meeting,
78
•The Digital Age will be to the Analog Age what the iron
age was to the stone age.
•And we can’t even imagine what the Post-digital Age will
look like. No more than Archimedes could imagine CERN.
Northwestern Central Bankers
meeting, Sept. 2015
Meeting,
79
Thank you
Milan Expo Meeting, Sept. 2015
80
As Freud said with masterly understatement in his The
Future of an Illusion, “While mankind has made continual
advances in its control over nature and may be expected to
make still greater ones, it is not possible to establish with
certainty that a similar advance has been made in the
management of human affairs.”
Milan Expo Meeting, Sept. 2015
81
Milan Expo Meeting, Sept. 2015
Milan Expo Meeting, Sept. 2015
83