[extropy-chat] Robin Hanson: The Next Really Big Enormous Thing

Hal Finney hal at finney.org
Sun Oct 10 03:59:07 UTC 2004


This was posted to WTA-talk, and I thought there would be interest in
it here.  As always Robin is provocative, and it is good to see his
ideas get a wider airing.  One thing I wonder about is Robin's other
essay http://hanson.gmu.edu/fastgrow.html, where he concludes,

"It seems hard to escape the conclusion that it just takes a lot of time
for the world economy to absorb even very broadly applicable technologies
like the computer, especially if the criteria of interest is raising
the rate of return on the marginal investment project worldwide. Thus
it seems unlikely that a single new technology could quickly knock the
economy into a high demand mode with very high growth rates."

It would be interesting to hear from Robin how to reconcile the difficulty
he notes here in kicking the economy into a new growth mode with his
prediction that uploads or some other computer technology could do
just that.

Hal

===

Robin Hanson: The Next Really Big Enormous Thing
Assistant Professor of Economics, George Mason University
http://www.futurebrief.com/robinhanson.asp
[16](read his bio)

    A postcard summary of life, the universe and everything might go as
    follows. The universe appeared and started expanding. Life appeared
    somewhere and then on Earth began making larger and smarter animals.
    Humans appeared and became smarter and more numerous, by inventing
    language, farming, industry, and computers.

    The events in this summary are not evenly distributed over the history
    of the universe. The first events are relatively evenly distributed:
    the universe started fourteen billion years ago, life appeared by four
    billion years ago, and on Earth animals started growing larger and
    smarter about half a billion years ago. But the other events are very
    recent: our species appeared two million years ago, farming started
    ten thousand years ago, industry started two hundred years ago, and
    computers started a few decades ago.

    Do we over-emphasize these recent events relative to their fundamental
    importance, because they are about our species and us? Are these
    events just arbitrary markers, chosen from thousands in a long history
    of relatively continuous change?

    I think not, and here is why: most of these events separate a chain of
    distinct exponential growth modes. (Exponential growth is where a
    quantity doubles after some time duration, then continues to double
    again and again after similar durations.) The growth rates of these
    modes have varied enormously.

    The slowest growth mode started first. Our fourteen billion year old
    universe is expanding, and that expansion is becoming exponential due
    to a mysterious "dark energy." The distance between the galaxies is
    predicted to double every ten billion years.

    We don't know enough about the history of non-animal life in the
    universe to identify its growth rates, but we can see that for the
    last half billion years the size of animals on Earth has grown
    exponentially. While the size of the typical animal is largely
    unchanged, the variation among animal size has greatly increased.
    Because of this, the mass of the largest animal has doubled about
    every seventy million years, and the mass of the largest brain has
    doubled about three times every hundred million years. So the largest
    brains have doubled about three hundred times faster than the distance
    between galaxies.

    Humans (really "our human-like ancestors") began with some of the
    largest brains around, and then tripled their size. Those brains, and
    the innovations they embodied, seem to have enabled a huge growth in
    the human niche - it supported about ten thousand humans two million
    years ago, but about four million humans ten thousand years ago.

    While data is scarce, this growth seems exponential, doubling about
    every two hundred and twenty five thousand years, or one hundred and
    fifty times faster than animal brains grew. (This growth rate for the
    human niche is consistent with faster growth for our ancestors -
    groups might kill off other groups to take over the niche.)

    About ten thousand years ago, those four million humans began to
    settle and farm, instead of migrating to hunt and gather. The human
    population on Earth then began to double about every nine hundred
    years, or about two hundred and fifty times faster than hunting humans
    doubled.

    Since the industrial revolution began a few hundred years ago, the
    human population has grown even faster. Before the industrial
    revolution total human wealth grew so slowly that population quickly
    caught up, keeping wealth per person at a near subsistence level. But
    in the last century or so wealth has grown faster than population,
    allowing for great increases in wealth per person.

    Economists' best estimates of total world product (average wealth per
    person times the number of people) show it to have been growing
    exponentially over the last century, doubling about every fifteen
    years, or about sixty times faster than under farming. And a model of
    the whole time series as a transition from a farming exponential mode
    to an industry exponential mode suggests that the transition is not
    over yet - we are slowly approaching a real industry doubling time of
    about six years, or one hundred and fifty times the farming growth
    rate.

    A revised postcard summary of life, the universe, and everything,
    therefore, is that an exponentially growing universe gave life to a
    sequence of faster and faster exponential growth modes, first among
    the largest animal brains, then for the wealth of human hunters, then
    farmers, and then industry. It seems that each new growth mode starts
    when the previous mode reaches a certain enabling scale. That is,
    humans may not grow via culture until animal brains are large enough,
    farming may not be feasible until hunters are dense enough, and
    industry may not be possible until there are enough farmers.

    Notice how many "important events" are left out of this postcard
    summary. Language, fire, writing, cities, sailing, printing presses,
    steam engines, electricity, assembly lines, radio, and hundreds of
    other "key" innovations are not listed separately here. You see, most
    big changes are just a part of some growth mode, and do not cause an
    increase in the growth rate. While we do not know what exactly has
    made growth rates change, we do see that the number of such causes so
    far can be counted on the fingers of one hand.

    While growth rates have varied widely, growth rate changes have been
    remarkably consistent -- each mode grew from one hundred and fifty to
    three hundred times faster than its predecessor. Also, the recent
    modes have made a similar number of doublings. While the universe has
    barely completed one doubling time, and the largest animals grew
    through sixteen doublings, hunting grew through nine doublings,
    farming grew through seven and a half doublings, and industry has so
    far done a bit over nine doublings.

    This pattern explains event clustering - transitions between faster
    growth modes that double a similar number of times must cluster closer
    and closer in time. But looking at this pattern, I cannot help but
    wonder: are we in the last mode, or will there be more?

    If a new growth transition were to be similar to the last few, in
    terms of the number of doublings and the increase in the growth rate,
    then the remarkable consistency in the previous transitions allows a
    remarkably precise prediction. A new growth mode should arise sometime
    within about the next seven industry mode doublings (i.e., the next
    seventy years) and give a new wealth doubling time of between seven
    and sixteen days. Such a new mode would surely count as "the next
    really big enormous thing."

    The suggestion that the world economy will soon double every week or
    two seems so far from ordinary experience as to be, well, "crazy." Of
    course similar predictions made before the previous transitions would
    have seemed similarly crazy. Nevertheless, it is hard to take this
    seriously without at least some account of how it could be possible.

    Now we cannot expect to get a very detailed account. After all, most
    economics has been designed to explain the actual social worlds that
    we have seen so far, and not all the possible social worlds that might
    exist. Even then we are still pretty ignorant about the causes of the
    previous transitions. But we do want at least a sketchy account.

    It turns out to be hard to create such an account using things like
    space colonization or new energy sources, mainly because we now pay
    only a small fraction of our budget on things like land and energy.
    But we pay seventy percent of world income for human labor, so
    anything that can lower this cost can have a huge impact. I am thus
    drawn to consider scenarios involving robotics or artificial
    intelligence.

    While machines have sometimes displaced human workers, they have much
    more often helped humans be more productive at tasks that machines
    cannot do. Machines have thus on net raised the value, and hence the
    cost, of human labor. And because people are essential, the limited
    rate of human population growth has limited the economic growth rate.

    Once we have machines that can do almost all the tasks that people can
    do, however, this picture changes dramatically. Since the number of
    machines can grow as fast as the economy needs them, human population
    growth no longer limits economic growth. In fact, simple growth models
    which assume no other changes can easily allow a new doubling time of
    a month, a week, or even less.

    Now admittedly, progress in robotics and artificial intelligence has
    been slow over the decades, primarily because it is so hard to write
    the software. And at these rates it could be centuries before we have
    software that can do almost all tasks that people do. The "upload"
    approach, however, of scanning human brains then simulating them in
    detail in computers, seems likely to succeed within the next half
    century or so.

    The transition from farming to industry seems to have been more
    gradual than the transition from hunting to farming. Even such a
    "gradual" transition, however, would be very dramatic. Assume that a
    new transition was as gradual as the one to industry, and that the
    world economic growth rate was six percent in both 2039 and 2040, plus
    or minus a typical yearly fluctuation of half a percent.

    If so, then in 2041, the increase in the growth rate might be the size
    of a typical fluctuation, and then in 2042 the growth rate would be a
    noticeably different eight percent. Growth would then be 14% in 2043,
    50% in 2044, 150% in 2045, and 500% in 2046. Within five years the
    change would go from barely noticeable to overwhelming.

    This is disturbing because human wages should fall quickly with the
    falling price of machines. So while humans who owned shares in the
    firms that made machines would get very rich, those whose only source
    of income was their labor could die of starvation. And if people wait
    to see the transition happen before they believe it is real, they
    might not have time to arrange for other sources of income.

    If we stand back from all the big events and innovations we have seen
    in the last century and look at the overall world economic growth
    rate, it seems surprisingly steady. All those events and innovations
    contribute to growth, but have not much changed the overall growth
    rate. From this, one might expect such steady growth to continue for a
    long time.

    Looking further back in time, however, we see that once in a while
    something has changed the growth rate by enormous factors in a
    relatively short time. We might do well to not ignore such a speeding
    freight train until it actually hits us.

    For more information see my papers:

    [17]Long-Term Growth As A Sequence of Exponential Modes

    [18]Economic Growth Given Machine Intelligence

    [19]If Uploads Come First

    This essay is original and was specifically prepared for publication
    at Future Brief. A brief biography of Dr. Hanson can be found at our
    main [20]Commentary page. Other essays written by Dr. Hanson can be
    found at his [21]web site. Other websites are welcome to link to this
    essay, with proper credit given to Future Brief and Dr. Hanson. This
    page will remain posted on the Internet indefinitely at this web
    address to provide a stable page for those linking to it.

References

   15. http://www.futurebrief.com/RobinHanson.pdf
   16. http://www.futurebrief.com/robinbio.asp
   17. http://hanson.gmu.edu/longgrow.pdf
   18. http://hanson.gmu.edu/aigrow.pdf
   19. http://hanson.gmu.edu/uploads.html
   20. http://www.futurebrief.com/commentary.asp
   21. http://hanson.gmu.edu/vita.html
   22. http://www.futurebrief.com/RobinHanson.pdf
   23. http://www.futurebrief.com/brief.asp



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