How Should We Measure Output and Productivity?
Let's now turn to the second question of how to best measure output and productivity. While there are some subtleties in measuring oil output, we know how to count barrels of oil. Measuring the overall level of goods and services produced in the economy is fundamentally messier, because it requires adding apples and oranges—and automobiles and myriad other goods and services. The hard-working statisticians creating the official statistics regularly adapt the data sources and methods so that, insofar as possible, the measured data provide accurate indicators of the state of the economy. Periods of rapid change present particular challenges, and it can take time for the measurement system to adapt to fully and accurately reflect the changes in the economy.
Let's now turn to the second question of how to best measure output and productivity. While there are some subtleties in measuring oil output, we know how to count barrels of oil. Measuring the overall level of goods and services produced in the economy is fundamentally messier, because it requires adding apples and oranges—and automobiles and myriad other goods and services. The hard-working statisticians creating the official statistics regularly adapt the data sources and methods so that, insofar as possible, the measured data provide accurate indicators of the state of the economy. Periods of rapid change present particular challenges, and it can take time for the measurement system to adapt to fully and accurately reflect the changes in the economy.
The advance of technology has long presented measurement
challenges. In 1987, Nobel Prize–winning economist Robert Solow quipped that
"you can see the computer age everywhere but in the productivity
statistics."6 In the second half of the
1990s, this measurement puzzle was at the heart of monetary policymaking.7 Chairman Alan Greenspan
famously argued that the United States was experiencing the dawn of a new
economy, and that potential and actual output were likely understated in
official statistics. Where others saw capacity constraints and incipient
inflation, Greenspan saw a productivity boom that would leave room for very low
unemployment without inflation pressures. In light of the uncertainty it faced,
the Federal Open Market Committee (FOMC) judged that the appropriate risk‑management
approach called for refraining from interest rate increases unless and until
there were clearer signs of rising inflation. Under this policy, unemployment
fell near record lows without rising inflation, and later revisions to GDP
measurement showed appreciably faster productivity growth.8
This episode illustrates a key challenge to making
data-dependent policy in real time: Good decisions require good data, but the
data in hand are seldom as good as we would like. Sound decisionmaking
therefore requires the application of good judgment and a healthy dose of risk
management.
Productivity is again presenting a puzzle. Official
statistics currently show productivity growth slowing significantly in recent
years, with the growth in output per hour worked falling from more than 3
percent a year from 1995 to 2003 to less than half that pace since then.9 Analysts are actively
debating three alternative explanations for this apparent slowdown: First, the
slowdown may be real and may persist indefinitely as productivity growth
returns to more‑normal levels after a brief golden age.10 Second, the slowdown may
instead be a pause of the sort that often accompanies fundamental technological
change, so that productivity gains from recent technology advances will appear
over time as society adjusts.11 Third, the slowdown may
be overstated, perhaps greatly, because of measurement issues akin to those at
work in the 1990s.12 At this point, we cannot
know which of these views may gain widespread acceptance, and monetary policy
will play no significant role in how this puzzle is resolved. As in the late
1990s, however, we are carefully assessing the implications of possibly
mismeasured productivity gains. Moreover, productivity growth seems to have
moved up over the past year after a long period at very low levels; we do not
know whether that welcome trend will be sustained.
Recent research suggests that current official statistics may
understate productivity growth by missing a significant part of the growing
value we derive from fast internet connections and smartphones. These
technologies, which were just emerging 15 years ago, are now ubiquitous (figure
3). We can now be constantly connected to the accumulated knowledge of
humankind and receive near instantaneous updates on the lives of friends far
and wide. And, adding to the measurement challenge, many of these services are
free, which is to say, not explicitly priced. How should we value the luxury of
never needing to ask for directions? Or the peace and tranquility afforded by
speedy resolution of those contentious arguments over the trivia of the moment?
Researchers have tried to answer these questions in various
ways.13 For example, Fed
researchers have recently proposed a novel approach to measuring the value of
services consumers derive from cellphones and other devices based on the volume
of data flowing over those connections.14 Taking their accounting
at face value, GDP growth would have been about 1/2 percentage point higher
since 2007, which is an appreciable change and would be very good news. Growth
over the previous couple of decades would also have been about 1/4 percentage
point higher as well, implying that measurement issues of this sort likely
account for only part of the productivity slowdown in current statistics.
Research in this area is at an early stage, but this example illustrates the
depth of analysis supporting our data-dependent decisionmaking.
The full speech is available, here. The paper concerning measuring value using volume of data, titled, "Accounting for Innovations in Consumer Digital Services: IT Still Matters," is available, here.
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