曝光臺 注意防騙 網曝天貓店富美金盛家居專營店坑蒙拐騙欺詐消費者

that control machine tools – were on the
horizon. Had computers created large-scale
unemployment, we should have seen the fi rst
signs by the end of the 1960s. In fact, the
opposite occurred.
For much of the 1970s and 1980s, the labor
force grew explosively as the baby boomers
matured and women of all ages moved into
paid work. The fast growth in the number
of potential workers meant that the number
of jobs had to grow rapidly to keep unemployment
from rising. In 1969, a boom year,
unemployment stood at 3.5 percent. In 2000,
another boom year, unemployment stood at
4.0 percent. In the intervening 31 years, total
employment grew from 83 million to 135
million – clearly not the picture once feared.
In Nobel Prize-winner Herbert Simon’s
1960 essay, “The Corporation: Will It Be Managed
by Machines?” Simon explained why
predictions of mass unemployment would
prove wrong. Borrowing from international
trade theory, Simon invoked David Ricardo’s
historic principle of “comparative advantage.”
Simon began from the premise that society
can always fi nd uses for additional output
(consider today’s unfulfi lled demand for
health care). Under this premise, computers
and humans will both be used in producing
this output, each in tasks for which they have
a comparative advantage. As Simon wrote:
If computers are a thousand times faster
than bookkeepers in doing arithmetic, but
only one hundred times faster than stenographers
in taking dictation, we shall expect
the number of bookkeepers per thousand
employees to decrease but the number of
stenographers to increase. Similarly, if computers
are a hundred times faster than executives
in making investment decisions, but
only ten times faster in handling employee
grievances (the quality of the decisions
being held constant), then computers will be
employed in making investment decisions,
while executives will be employed in handling
grievances.
Note that in Simon’s examples (as in Ricardo’s
original formulation), computers are
more effi cient than humans in both tasks, but
employing humans is still worthwhile in tasks
in which they have a comparative (that is, relative)
advantage. As we know, our current situation
is not this extreme since humans are
more effi cient than computers in understanding
speech, interpreting visual images and in
a host of other activities requiring recognition
of complex patterns. At the same time,
Simon does not rule out that the adoption
of computers may cause painful adjustments,
or that workers displaced by computers may
regain employment only at lower wages – at
least in the short run.
The story Simon describes has played out
with many technologies. When the combine
harvester came into widespread use in the
1920s, it displaced manual labor and created
substantial rural unemployment. Over the
longer run, most farm workers were reemployed
through either of two channels. In the
Had computers created large-scale unemployment,
we should have seen the first signs by the end of the
1960s. In fact, the opposite occurred.
66 The Milken Institute Review
fi rst, greater effi ciency in agriculture meant
that farm products could be sold at lower
prices, so consumers could increase purchases.
Workers were rehired to help produce the
larger levels of output now demanded by
consumers.
In the past 20 years, this channel has characterized
“back-offi ce” jobs in the securities
industry. Consider the entry-level accountants
who keep the books for mutual funds
and compute the net asset value per share
that appears in daily newspaper stock tables.
Over two decades, the computerization of
their job has allowed the average accountant
to keep records for four mutual funds instead
of one or two. Had the number of funds
stayed constant, the accountants’ greater productivity
would have meant fewer accounting
jobs. But over the same period, the number
of mutual funds expanded from 500 to 5,000
and the number of fund accountants significantly
increased. The growth in the number
of mutual funds stemmed, in part, from
the decline in the cost of running a mutual
fund as computers lowered the costs of record
keeping, trade execution and other backoffi
ce functions.
The second, more important channel of
re-employment was the movement of displaced
workers into other, expanding industries.
In the fi rst half of the 20th century, large
　
中國航空網 www.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：航空資料22(3)