When economists debate economic stagnation, I routinely recall my undergraduate macroeconomics textbook, Dornbusch and Fischer’s Macroeconomics (5th edition). In Appendix 2-1, these famed economists introduce readers to two main contrasting price indices: the Laspeyres, or base-weighted, and the Paasche, or current-weighted:
While this may seem technical, much is at stake. Suppose a stagnationist belittles the economic importance of the internet. “So we get some free stuff. How much can it possibly shift official GDP calculations?” The answer: Tremendously. Why? Because calculations of real GDP use the GDP deflator, and the GDP deflator uses a Paasche price index.
Let’s set our base year to 1990 – the very year my old textbook was published. Now consider Youtube. Its measured annual contribution to GDP is about $15 billion. Relative to GDP, that’s a pittance, right? But Youtube consumption is about 1.5 billion hours per day. Back in 1990, a typical video rental cost $2.49. So even ignoring the massive increase in consumer choice and convenience, the annual contribution of Youtube measured in base year prices is 1.5B*$2.49*365. That’s roughly $1.4 trillion dollars. Paasche power!
The results for Google are even more dramatic. People run an average of 3.5 billion searches a day. Back in 1990, you would have been lucky to get comparable service for $20 – perhaps by hiring someone to spend a couple hours poring through the Reader’s Guide to Periodical Literature. So while the value of Google’s services in current prices is about $100B a year, the value in base year prices comes to over $25 trillion dollars.
You can see where this is going. If we sum the current revenue of the top internet companies, it’s probably well under $1T per year. However, if we sum the value in 1990 prices of the cornucopia they provide, it easily exceeds $50 trillion a year. Yes, much of this consumption happens abroad, increasing Gross World Product rather than U.S. Gross Domestic Product. Yet using a Paasche price index, there’s still no doubt that the GDP deflator has sharply fallen since 1990. That means decades of non-stop deflation. This in turn implies that real GDP has risen far more than almost any respectable economist will admit.
Switching to the Laspeyres price index naturally makes this stunning result go away. If we take 1990 output at today’s prices and divide it by 1990 output at 1990 prices, we’ll only see modest progress. A few sectors – like video rental – will basically vanish from the numerator, but they’re only a small component of the denominator. For example, using a base-weighted index, the value of video rentals in 1990 at today’s prices is roughly zero because video is now virtually free. But the value of video rentals in 1990 prices is also modest, because when video was $2.49 a pop, total consumption was modest.
So which method of price indexation is correct? Once they understand what’s at stake, dogmatic optimists will say, “Paasche!” Dogmatic pessimists will naturally answer, “Laspeyres, of course.” I say both sides should be more broad-minded. Yes, there is a sense in which progress since 1990 has been modest. However, there is another important sense in which progress since 1990 has been astoundingly awesome.
If you don’t remember 1990, the modern world is easy to take for granted. The rest of us, however, know – or at least ought to know – that modernity is a living miracle. Though we don’t own fifty cars each, we still enjoy fabulous luxuries beyond the budget of the richest residents of 1990. Stagnationists live to belittle these gains, but that’s not science; it’s perspective. Paasche points the way to a radically different yet equally scientific conclusion. The judicious approach, though, is not to pick a side, but to triangulate. Economic progress is complex. In some major ways, it’s been slow; in other major ways, it’s supersonic. And overall? Seems speedy to me – and not because I don’t know the numbers.
READER COMMENTS
Swami
Mar 28 2019 at 2:25pm
I think we need to spend more time contemplating the Paashe method. Private letters used to cost about 25 cents each back in 1990. Now we send billions of them per day for free (and a same day message would have cost closer to a hundred dollars each). How many trillions of gain is ignored?
It also cost close to $500k each to build a teleconference room (with tens of thousands in annual maintenance costs and rents for the dedicated space). Now it is a free app on every smart phone sold globally. How many trillions are ignored?
Steve Horwitz
Mar 28 2019 at 4:04pm
Seems to me this is another way of looking at Nordhaus’s point that innovators keep only about 2% of the value they create. The rest is consumer surplus.
Philo
Mar 28 2019 at 4:59pm
How about goods or services that are available now (for some finite price) but that were not available at all in 1990? In 1990 their price was infinity, so, using the Paasche deflator, deflation has been massive, indeed!
Jeff Hummel
Mar 28 2019 at 5:08pm
This post is a bit outdated in one respect. Although the BEA still reports a GDP deflator that is based on a Paasche index, you have to dig into their webpage to find it. Decades ago the BEA converted to estimating reported real GDP with a chain-weighted price index, which is supposed to avoid the upward substitution bias of a Laspeyres index and the downward substitution bias of a Paasche index. And recent estimates of past real GDP have been revised to reflect this change. Of course, this actually strengthens your conclusion.
Matthias Görgens
Mar 29 2019 at 12:54am
The discussion is fascinating. I guess the takeaway for monetary policy is:
Measuring broad inflation is hard, because it tries to couple nominal and real variables. Even defining inflation is non-trivial. (Same for the general price level, since inflation is just its first derivative.)
You can avoid some of those pitfalls by picking a simpler basket (like eg average hourly wages or a Big Mac).
Or you can target something almost purely nominal like nominal GDP or total nominal wages per worker.
(Of course, the definitional trouble with inflation isn’t the end of the world for an inflation target. Just pick a halfway sensible measure to target and stick to it. There’s no God given Right Target.)
robc
Mar 29 2019 at 8:40am
Calculating inflation is easier (somewhat) if you define it as monetary inflation. Change in M2 (or M3 or whatever) year-over-year is still not a perfect calculation, but a lot easier* than trying to do some basket of goods.
And I think it is a more useful measure too.
*I think, but maybe it isnt?
Thaomas
Mar 30 2019 at 8:36am
The implication for policy is not evident. Whatever price index chosen, the “stable prices” part of the Fed’s dual mandate ought to mean keeping that index growing at the target rate. Policy under NGDP targeting would also be unchanged although the target rate (what nominal increase in NGDP rate “feels like,” is estimated to be, consistent with maximum real growth) might be different in a Paashe world versus a Laspeyres world.
Vladimir Antimonov
Mar 29 2019 at 6:49am
The statement that “…video rentals in 1990 at today’s prices is roughly zero because video is now virtually free” is incorrect. Quality aside, renting a movie on iTunes costs roughly the same as renting a VHS 29 years ago. The new “virtually free” services like YouTube or Google are something that is consumed instead of other virtually free services in 1990s – like walking, or reading a book, or talking to a friend, for instance. Supporting this view is the fact that not more than 2 million people in the US bother to pay even a meagre $12/month for the YouTube premium to watch videos ads free, so the average value of one view must be really close to the price of one ad. Therefore most of the respected economists are right to think that the 1.5B*$2.49*365 calculation is insane. These new cheap, high-quality internet services definitely increase GDP and well-being, but are irrelevant for the price index calculation.
P.S. Completely agree that progress since 1990 has been awesome.
William Ehlhardt
Mar 31 2019 at 4:15am
This is getting at something important: decreasing marginal benefit. Yes, there are 1.5 billion video rental equivalents provided by YouTube per day, but are they all worth $2.49?
If people were renting only, say, 0.5 billion videos a day in 1990, then that’s probably because the other 1 billion video rental equivalents were worth less than $2.49 and still are.
Treating those extra 1 billion video rental equivalents as having the same $2.49 value each seems certain to wildly overstate the impact of YouTube.
Vladimir Antimonov
Mar 29 2019 at 7:19am
The statement that “…video rentals in 1990 at today’s prices is roughly zero because video is now virtually free” is incorrect. Quality aside, renting a movie on iTunes costs roughly the same as renting a VHS 29 years ago. The new “virtually free” services like YouTube or Google are something that is consumed instead of other virtually free services in 1990s – like watching TV (TV consumption peaked around 2009), or talking to a friend, or going to a library. Supporting this view is the fact that not more than 2 million Americans bother to pay even a meagre $12/month for the YouTube premium to watch videos ad-free, so the average value of one view must be somewhere close to the price of one ad. People also do not seem to tolerate as much as one small banner as a price for searching. Therefore most of the respected economists are right to think that the 1.5B*$2.49*365 calculation for YouTube and $20 per search for Google is insane. These new cheap, high-quality internet services undoubtedly increase GDP and well-being, but have negligible impact on the price index.
Daniel Hill
Mar 29 2019 at 9:40am
But in most major cities there are more than fifty cars just waiting for you to summon them through your smartphone…
Thaomas
Apr 1 2019 at 3:11pm
Whatever the way of measuring inflation, it still needs to be validated by experience. How politically popular or unpopular is the number? What number seems most consistent with growth?
Ricardo
Apr 1 2019 at 5:46pm
“But YouTube consumption is about 1.5 billion hours per day”
Remember, however, that although the CPI is considered a quantity-weighted index, the quantities are not actually measured… instead, expenditures are divided by prices. In cases like YouTube, search, etc., consumer expenditures would be close to zero, and would have little effect on the index (as currently constructed).
Comments are closed.