The 75 per cent solution: tourism

by John Quiggin on December 15, 2007

A lot of discussion of climate change is based on the implicit or explicit premise that, since we use energy in everything we do, and most energy is derived from carbon-based fuels, large reductions in CO2 emissions will require radical changes in the way we live. Some people welcome this prospect, but most do not.

Having looked at this problem in various different ways, I’m convinced that this premise is wrong, and that quite modest changes, many of which would follow more or less directly from the imposition of a suitable cost on CO2 emissions, could achieve large reductions in emissions. I’ve argued this at the macro level, based on demand elasticity estimates, and also at the micro level in terms of road transport. I thought it might be a good idea to attempt more micro estimates and, as I was visiting Cairns last week[1], my thoughts naturally turned to long-distance tourism.

So, this is hoped to be the first in a series where I consider the question: Could we reduce emissions in a given sector of the economy by 75 per cent in a way that wouldn’t substantially change the services delivered by that sector?

A few ground rules for the exercise before I start – there may be more as I go along.

1. I’m looking at changes over a time span of a few decades, enough that existing capital stocks are turned over. So I assume that price incentives are enough to encourage a shift to the most fuel-efficient technologies currently in use, but I don’t make any big assumptions about future innovations induced by higher prices. To take the road transport example, I can assume replacement of Hummers by Prius (BTW, what is the plural of Prius?) but I don’t invoke hydrogen fuel cells or similar exotica.

2. I’ll take it as given that the services enjoyed in the late 20th century qualify as not involving radical changes. In the case of road transport again, I might assume a return to the vehicle occupancy rates of 1990 (about 10 per cent higher than today).

3. I’m looking at reductions in emissions to deliver the existing volume of services, not taking account of growth in demand, which needs separate assessment. It’s just an exercise in arithmetic to combine the two. For example, if you predict a 60 per cent increase in demand under business as usual, then a 75 per cent reduction brings total emissions back to 40 per cent (0.25*160) of the original level, which is about what is probably needed to stabilise climate.

With these ground rules, the case of long-distance tourism turns out to be surprisingly easy, especially thanks to this piece by Justin Rowlatt who’s already looked at the question. The current airline fleet has a fuel efficiency of around 4.8 litres/passenger/100 km. [2] Replacing this fleet with the models now being introduced, the Boeing 787 and Airbus A380, will reduce this by about 50 per cent . This is going to happen anyway, and the only role for higher prices is to accelerate the scrapping of the older planes in the existing fleet.

To get a further 50 per cent reduction is even easier (this was the idea that got me started). All you need to is double the length of the average holiday and halve the frequency. I don’t have good numbers, but it’s clear that this would just take us back to the situation that prevailed a few decades ago when air travel was more expensive. Going back a bit further, travel was so expensive that young Australians typically planned a single trip to England that was to last a year (and, as far as such travel was concerned, a lifetime).

Two reductions of 50 per cent combine to give 75 per cent, so it’s all done. But that was so easy, it seemed worth trying for more. What would be involved in reducing emissions by 85 per cent, from 25 per cent of the original level to 15 per cent? That requires a further 40 per cent.

According to the International Air Transport Association, cited by Rowlatt, there’s an easy (in terms of impact on travellers, at any rate) 12 per cent to be gained from improved air traffic control. You could get another 12 per cent (at least) by packing more economy seats into planes (the A380 can take 800, at which Rowlatt estimates fuel consumption of 1.9 l/100 pkm. For the final leg, we’ll need the first actual cut, a 25 per cent reduction in the number of long-distance trips, to be replaced by local holidays with extra spending money from the saving in travel costs.

So, to sum up, let’s look at the impact of an 85 per cent reduction in emissions, achieved as outlined above. Suppose the baseline is eight one-week long-distance holidays over some given period. After the 85 per cent reduction we’d have three two-week long-distance holidays and two one-week local holidays instead. On the plane, we’d be packed in about as tight as at present, maybe a bit less so, and of course there will be lots of nice new features like free WiFi to keep us entertained.

Even with a hefty surcharge on emissions, total expenditure on airfares would fall, so there would be more money to spend on the actual holiday, not to mention the flow of revenue to governments that could be returned in tax cuts or improved services.

No doubt all this would take some adjustment. But The End Of Civilisation As We Know It, it’s not.

fn1. Not a tourist trip. I was at a meeting looking at how, if at all, coral reefs can be saved from climate change. But the contradictions involved in flying 1000 km to such a meeting and in the hope that demand from the tourist industry will push governments into action, were obvious enough.

fn2. Because airplane emissions are injected directly into the upper atmosphere, where they do more damage, this figure can’t be compared directly with fuel efficiency measures for cars. Roughly speaking, you need to double the airplane emissions figures before doing a comparison. Of course, that doesn’t affect the calculations that follow which are all about proportional reductions.

{ 1 trackback }

The Ambrosini Critique » Blog Archive » Reducing CO2 emissions by 75% will be painful, right?
12.15.07 at 6:00 am

{ 68 comments }

1

improbable 12.15.07 at 5:27 am

“this would just take us back to the situation that prevailed a few decades ago when air travel was more expensive.”

Does anyone have a good source of historical air travel prices? Ideally for long routes I guess. It’s easy to remember (possibly second-hand!) it being expensive enough that people did less of it, but harder to remember just how expensive. This might give some estimate of how much fuel prices would have to change for the scenario you describe.

2

a 12.15.07 at 5:36 am

I guess that excludes Americans continuing to go to Europe for their two-week holiday. Are they supposed to take a four-week holiday every two years?

3

a 12.15.07 at 5:39 am

Or: Being on the other side of the pond, I take a three-week holiday in the States. Now I have to take a six-week holiday? That’s an awfully long time and I wouldn’t be able to continue in my current job.

4

Rich Puchalsky 12.15.07 at 5:39 am

People consistently don’t realize the advantage of efficiency improvements for CO2 reduction. If you want to reduce the emissions of ten coal-burning power plants by 10%, you could tear one down and replace it with a nonpolluting wind power farm or something. Or you could replace the turbines at all of them to get 10% more efficiency, for the same effect. Of course you want to tear down the coal-burning plants and replace them, too, but you don’t have to wait to build all that infrastructure.

5

John Quiggin 12.15.07 at 6:01 am

“I guess that excludes Americans continuing to go to Europe for their two-week holiday. Are they supposed to take a four-week holiday every two years?”

Well, as I said, a four-week holiday every two years doesn’t sound like The End Of Civilisation As We Know It to me. Nor does the notion of allowing employees to accumulate leave.

A big problem here is that a lot of people seem unable to conceive of any points between “going on exactly as we are” and “economic cataclysm”.

6

Walker 12.15.07 at 6:23 am

You could get another 12 per cent (at least) by packing more economy seats into planes (the A380 can take 800, at which Rowlatt estimates fuel consumption of 1.9 l/100 pkm.

You are obviously very short.

Economy class is currently uncomfortable for anyone over 6′ 3″, even if the person in front does not lean back; when the person in front does recline, it is incredibly painful. There is not a lot of play in the spacing of economy seats, which is why Airlines have stabilized them where they are, after significant attempts to reduce leg-room since the 90s.

7

Matt McIrvin 12.15.07 at 6:36 am

a, I think you vastly overestimate the length of American vacations. A two-week holiday is not unheard of, but is not the norm–if people took them, that would pretty much be the change Quiggin is looking for.

Multiple extended weekend trips are more common, and the year’s long vacation might be a week long.

8

John Quiggin 12.15.07 at 7:18 am

#7, as I understand it, the 800-seat configuration is all-economy, but no different from existing economy class as regards leg room.

On a side point, why do airlines allow reclining seats at all? They are the ultimate negative sum game, except when the plane is half-empty.

9

Bruce Baugh 12.15.07 at 7:34 am

Matt’s #8 matches my understanding of the American situation both anecdotally and based on statistics over the decades. Not many Americans get even one full week that they can use for a trip each year; popular destinations like Las Vegas and Disney World pitch a lot of package deals for Thursday or Friday through Monday or Tuesday. So while I agree that this would be an excellent change, I don’t think it’s obtainable without the same restructuring of American labor relations that’s the key to a lot of other things that really should happen.

10

Matt Kuzma 12.15.07 at 7:39 am

I would also like to make it clear that electric planes are not infeasible. As in, I’ve seen the patents on them. So even long after oil reserves have dwindled to near-nothing, current per-capita air travel rates will still be possible.

11

Tim Worstall 12.15.07 at 10:18 am

There’s two further technological changes that make this specific example, air travel, even easier to get to such large reductions in emissions. They meet John’s criterion of happening over decades as capital stocks turn over.
Sorry if this is a little technical as it comes from the day job.
1) Making wing surfaces from an aluminium scandium alloy, rather than the aluminium alloy currently used (the actual Sc addition is small, about 0.2%). This means that the upper surface does not need to be painted or lacquered in order to get the necessary efficient airflow. Seems like a minor point but that saves 1-2% of the weight of the aircraft, with obvious fuel savings on every trip. Airbus has been working on this for a decade now (the basic idea is simple enough. It’s rather that they’ve got to build an entire wing, then stress test it, ice it, spray it with deicer, salt water etc. etc etc. to make sure that it is indeed as reliable as the current alloys.) and my information is that this is looking good to go.
2) There’s a more speculative idea to do with welding. Welding aluminium is a bitch: the weld itself is usually weaker than the surrounding material. This is in contrast with steel, where the weld is stronger than the surrounding plate. The addition of scandium (how did you guess that my day job is selling scandium?) to both the alloy and the weld wire (again, 0.1-0.2%) reverses this situation.
There’s a project between Airbus, U of Oxford, QinetiQ and a few others to develop this (friction stir welding it has been called) so that the fuselage of aircraft will be welded rather than the current rivetting. This saves a further 10% of the weight of the airframe. With, obviously, knock on effects on fuel consumption.
This second project is still in the early years of the 10-15 year testing process for such new technologies in aircraft. It’s already used in bicycles, but we tend to worry less about the reliability of a bike frame than we do an airframe.

Sorry about the tecchie bits there but I think John is largely correct, in many fields there are such reductions in emissions to be had which won’t mean the end of the world as we know it with what I think is the crucial proviso: as long as we are looking at things which kick in as the capital stock is replaced in the normal cycle.

12

Quo Vadis 12.15.07 at 11:41 am

The easiest place to look to individual reductions in carbon emissions is in our work processes. For many types of work, telecommuting, teleconferencing, web conferencing etc. are very efficient ways to work, but there are cultural and process barriers that have so far prevented companies from adopting these approaches on a large scale. Many managers don’t feel comfortable with telecommuting because haven’t don’t have effective metrics to measure productivity and so don’t trust their employees to manage their own time and they haven’t developed their communications processes beyond the need for frequent ‘face-to-face’ meetings. I used to work for a company in California that was bought out by a large publisher on the east coast. They used to fly teams of managers out every week for meetings. They claimed it was necessary, but we thought they were nuts.

I think a concerted effort to develop and promote the necessary business processes and technologies and to create incentives for their adoption could yield much greater results with less pain than limiting people’s leisure activities.

These days I work almost entirely from home. I do consulting work and charge my customers a higher rate if I have to work on-site. My work-related carbon footprint consists of the energy required to run my computer. I put gas in my car two or three times a year (good public transit here). On a nice day I go to the beach or for a hike and I’m learning to cook. The low carbon life is good.

13

Great Zamfir 12.15.07 at 11:53 am

I am sorry, but at the information you are getting from the Rowlatt piece is far too positive.

Rowlatt achieves his ‘simple reduction by 50%’ by comparing the numbers aircraft manufacturers publish to look clean with the numbers achieved in reality for existing aircraft. To get those numbers, the manufacturers are pushing the envelope of realism.

The 4.8 number for existing aircraft is based on actual number of passenger kilometers in a year divided by actual fuel used. The new numbers for the future are based on ‘perfect’ flights, medium-range, 100% passenger capacity, no extra miles to fly around airports while waiting, etc. In real life, a shorter than medium flight will have higher specific fuel burn because initial climb is a larger part of the flight. Longer range flights need to carry extra fuel weight, and are therefore less efficient. So the numbers given by the manufacturers are not exactly lies, but they are too rosy.

A second point is that the new aircraft whose predicted figures are used are long-range aircraft. Long range aircraft are the most efficient around, because fuel burn is a large part of their operating cost. Of course, the current 4.8 number also includes the EasyJet-style short range aircraft, designed for lower cost but higher fuel burn. If you want to compare apples to apples, you should compare next-generation long range aircraft to current-fleet long range aircraft, bringing the current number closer to 4.2 or so, thus decreasing the relative gain for the new aircraft .

Finally, Rowlatt magically improves the fuel consumption of an A380 by giving it all-economy seating. While this would certainly decrease fuel consumption per passenger-kilometer, the improvement would not be as much as he believes.Adding 300 passengers, plus their luggage and chairs will increase the weight of the aircraft, meaning it will have higher fuel burn. To still reach its destination, it needs extra fuel. The extra fuel makes it even heavier, so it needs even more fuel. For intercontinental flights, the extra fuel can be several times the weight of the extra passengers. So, adding extra seats will not improve fuel consumption per passenger as much as he hopes.

To make a long story short: yes, new aircraft are better than the old ones. But not as much as their own, cherry-picked numbers suggest.

14

Great Zamfir 12.15.07 at 12:19 pm

@ Tim Worstall: you’re of course right when you say that many improvements are still possible. But I think at present technology progress is decreasing fuel burn at 2 or 3% each year, while consumption is growing 5 to 6% each year. All the progress being made is only slowing the growth in fuel use and CO2 production, and is far from decreasing it.

On a tech-to-tech note, do you know what they are planning to use the scandium alloys for? I think the decision to use carbon wings on A350 is pretty fixed. Is this a hint that they expect the A320 replacement will have metal wings, or is it for future A380 wings?

15

richard 12.15.07 at 12:22 pm

…which is about what is probably needed to stabilise climate

Source?

You are obviously very short.

while we’re speculating about forcing social change through pricing, this might be a viable long-term strategy, too: taller really isn’t better for us, health-wise or energy-wise, and yet we keep getting taller here in the US, decade by decade, and regarding it as proof we must be doing something right. If it’s relatively easy to get the whole population to change its habits as John suggests, why not make a few adjustments to the national diet, restricting early intake of protein to a healthier level?

I’ll bet once we’ve beaten the obesity problem it’ll be a breeze.

16

Tim Worstall 12.15.07 at 12:28 pm

“or is it for future A380 wings?”

As far as I know, yes. But then I’m not in the planning decisions: I just supply the material.

17

John Quiggin 12.15.07 at 2:00 pm

Zamfir, the 2.4 number quoted by Rowlatt is claimed to be for a two-class configuration with 90 per cent occupancy, so it appears your correction has at least overstated the error in the comparison.

18

Matt McIrvin 12.15.07 at 2:34 pm

taller really isn’t better for us, health-wise or energy-wise, and yet we keep getting taller here in the US, decade by decade, and regarding it as proof we must be doing something right.

I thought that had slowed or stopped more recently (Northern Europe has definitely overtaken us).

19

Total 12.15.07 at 2:35 pm

If it’s relatively easy to get the whole population to change its habits as John suggests, why not make a few adjustments to the national diet, restricting early intake of protein to a healthier level?

Can I have a pony, too?

20

Great Zamfir 12.15.07 at 2:41 pm

18. : I am highly skeptical about the 2.4 number. As you can see, Airbus claims 2.9 for the A380 at 525 seats, which is close to full capacity in standard lay-out. I know that in its marketing towards airliners, Boeing is not claiming better fuel use per passenger than the A380, but almost comparable or slightly worse. Given that the 787 is half as big as the A380 and larger planes tend to be more efficient, just being comparable to the A380 is already a bold claim.

Now the 2.4 number would suggest that the 787 is a lot more efficient, even at 90% capacity. So these numbers cannot be both correct. I seem to remember the 2.9 Airbus figure, and it was based on pretty much the calculation I described. So I guess the 2.4 l/paxkm number is something Boeing’s marketing department dreamed up using even more distorted calculations than Airbus ( for example, only looking at cruise and ignoring take-off completely, or assuming a larger fraction of the fuel to carry cargo, since long-range planes carry both at the same time).

Remember, airlines don’t look at these l/paxkm numbers. They get tables showing the fuel consumption of the entire aircraft, given a certain payload in tonnes, under a range of condition. They calculate for themselves what that means for their situation.The figures we are looking at are meant for public consumption, to show that planes are comparable to cars, and if airlines know that they are unrealistic, they won’t complain, since they need the same aircraft are clean image.

A much more realistic figure is the percent improvement Boeing and Airbus are claiming themselves. Airbus claims a 12-15% improvement of the A380 over the 747-400, Boeing a 15 % improvement for its (yet unbuilt) 747-8 over the 747-400, and a 20% improvement of the 787 over its predecessor 767. Nowhere near the figures Rowlatt sees.

21

Slocum 12.15.07 at 4:00 pm

I think Quiggin is right that a 75% reduction in greenhouse gases from air travel wouldn’t, by itself, mean the end of civilization as we know it (I’m pretty sure it wouldn’t even mean the end of thousands of bureaucrats and activists flying from the ends of the earth to tropical beach resorts during northern winter for environmental conferences).

But I think Quiggin’s wrong to suggest that the changes he envisions would make very little difference. Half the trips (twice as long or not) would mean half the number of aircraft and flights. This would mean a massive shrinkage in the size of the aircraft and airline industries. Look at the current angst over troubles at Airbus and imagine what they would be if prospects were for the company shrinking by half (or one of either Airbus or Boeing going under).

And would trips really be twice as long? That seems very unlikely. Most people I know like their leisure consistently, and wouldn’t be willing to forgo a trip during the odd years in order to take a double-length vacation during even years. The situation when I was a middle-class kid in the 60’s and 70’s was that we just didn’t fly. My parents flew occasionally, but it was too expensive to load up the whole family — I took a trip in an airliner exactly once before I was an adult. Family trips were by station wagon. We’ll be returning to a situation where only rich people fly regularly and middle class people fly rarely or never (which would help restore the ‘lost elegance’ of air travel, I suppose).

And realize the impact on destinations would be far from uniform. Right now, we are worrying about the effect of rising sea levels on remote atolls. But flights to these distant locations would become prohibitively expensive. For the few rich people who could still afford to go, these places would be much less infested by ordinary tourists, but the effect on tourism-dependent economies would be severe.

And we have to expect that the effect on business travel would be equally strong. I would say that most business (and academic) travel is pretty wasteful as it is, but the effects on the hotel and restaurant businesses from shrinkage also would be severe.

Taking a step back from the travel industry, the kinds of changes envisioned at Bali cannot help but mean that developing nations would add a major energy/carbon cost advantage to their existing labor cost advantages. What effect would this have on the economies in the developed world?

Consider that, already, in the U.S. without recession and without carbon limits and taxes, there is growing populist sentiment against ‘unfair’ trade advantages by China. What would be the political effects of imposing 25-40% carbon reductions on the U.S. in the next decade while China continued on with no (or minimal) restrictions?

People living in societies with growing economies tend toward tolerance (see, for example, The Moral Consequences of Economic Growth) — but not so people living in societies experiencing economic stress and decline (xenophobia is more likely).

Yes, we can imagine the possibility of a recognizably modern world with much less air travel, but can we get there from here without massive dislocations?

22

Cian 12.15.07 at 4:51 pm

#22 Those are not massive dislocations. Hell you’re not even talking about dislocation at the level of the 70s oil shock.

23

Alex 12.15.07 at 4:59 pm

Propfans: the GE testbed (an MD90) was about 30 per cent less thirsty than a stock job. They are noisier, but then I live near Heathrow and I suspect I can stick a marginal increase in noise better than the consequences of my neighbourhood becoming the Featherstone of the 2010s.

24

Brett Bellmore 12.15.07 at 5:08 pm

“On a side point, why do airlines allow reclining seats at all? They are the ultimate negative sum game, except when the plane is half-empty.”

Not on a night flight, when everybody is reclining.

“And would trips really be twice as long?”

Not bloody likely: We have a saying where I work; “If we could do without you for that long, we could do without you.”

25

clew 12.15.07 at 7:33 pm

Since the standards of employment vary a lot from industry to industry, and even within an industry have sometimes varied in my working lifetime, I know we could change them again, if there was a good payoff (like having vacations abroad).

To respond to brett bellmore’s point, it was Understood at Microsoft Languages in the late 90’s that if your work wasn’t clear and documented well enough to be picked up by the group ‘if you got hit by a bus’, you weren’t working like a real professional. There’s as much stylistic posturing in that as there is in b.b.’s group’s rationalization. We’ll tell a good story for the New Normal, no matter what Normal is.

The problem, at Microsoft, was that long vacations are so much better than short ones that those of us who took them were often inspired not to come back at all. Of course, being able to not come back is not usual in any economy, so perhaps we needn’t worry about it. Also, it was very pleasant to be working only with people who wanted to be working, and raised group efficiency a lot.

26

Frederick Guy 12.15.07 at 7:39 pm

22. “And we have to expect that the effect on business travel would be equally strong. I would say that most business (and academic) travel is pretty wasteful as it is….”

Business air travel has changed the way business is done. The international eoonomy is different today from what it was thirty years ago not so much because of higher volumes of trade, as because supply chains and even R&D collaborations are arranged across borders, continents, oceans. This doesn’t work without *lots* of face-to-face meetings, hence flights. There is a very large class of business people who live in the air now, for this reason.

How large a rise in cost/reduction in service frequency would be needed for a large reduction in business travel? Don’t know, but if it happens the implications go much beyond reducing waste – it would be a restructuring of international business.

27

Slocum 12.15.07 at 8:15 pm

The international eoonomy is different today from what it was thirty years ago not so much because of higher volumes of trade, as because supply chains and even R&D collaborations are arranged across borders, continents, oceans. This doesn’t work without lots of face-to-face meetings, hence flights. There is a very large class of business people who live in the air now, for this reason.

I don’t think we know that ‘this doesn’t work without lots of face-to-face meetings’ because we haven’t really tried to do without them yet–ubiquitous, low-cost, high-speed audio and video communication is a much newer phenomenon than fast jet travel.

I would say that at this point, quite a lot of business travel falls into the category of ‘signaling’ — you fly ‘over there’ to ‘show the flag’ and to demonstrate that you are serious about the relationship.

Recall that levels of globalization were very high before WWI, even though high-speed international travel did not exist.

28

John Quiggin 12.15.07 at 9:49 pm

Following up #23, the changes I’m talking about will , for the average person, be impossible to discern against the background of thirty years of economic growth and changes in other relative prices. As an example, if the price of health care continues to rise as it has done, while the price of anything computable continues to fall, these changes will have a massively bigger impact than those discussed above.

29

James Robertson 12.15.07 at 10:14 pm

“I don’t think we know that ‘this doesn’t work without lots of face-to-face meetings’ because we haven’t really tried to do without them yet—ubiquitous, low-cost, high-speed audio and video communication is a much newer phenomenon than fast jet travel.”

Hmm. I work in a highly distributed company (geographically), and I can tell you that virtual meetings are necessary, but you absolutely have to have regular face to face ones. You simply cannot underestimate the importance of body language, especially when there are disagreements. This is especially critical in any global company where you have meetings with people from different nations/cultures.

I work in this arena now, and I can tell you – your theory about this is just wrong. Lots of companies are trying to minimize the number of trips required, but they have found that you simply cannot eliminate them all.

30

Chuckchuck 12.15.07 at 10:37 pm

Jets pollute the atmosphere in a unique way. There is very little mixing between the troposphere (where plants and the seas can sequester CO2) and the stratosphere where CO2 can sit for decades. Jets spend most of there fuel in the stratosphere. That with the blanket effect of contrails makes jet transport probably the most damaging of the modern machines to the atmosphere.

It has been documented that after 9/11, when jet travel was banned, there was a noticeable cooling over north america. You want Greenland to stop melting, stop flying over it.

31

Badger 12.15.07 at 10:43 pm

I’m finding this whole discussion very educational, and I hope future installments will be equally reader-friendly.

What about this issue of fuel-consumption improvements in new models, per-passenger versus the raw figures? Are the raw figures corporate secrets? If they were available might using them be semi-fatal to the overall argument here?

32

Barry 12.15.07 at 10:48 pm

“Lots of companies are trying to minimize the number of trips required, but they have found that you simply cannot eliminate them all.”
Posted by James Robertson

Just to help a bit with the logic, ‘trying to minimize the number of …’ is quite compatible with , say “chopping in half”, or “chopping in a quarter”. Those last to phrases are not contraindicated by ‘cannot eliminate them all’.

As slocum has pointed out, we’ve had decent international videotelecommunications for not that long.

33

James Robertson 12.15.07 at 11:37 pm

Decent international video communication? Assuming:

– all parties involved work out of offices, not the home
— all parties involved have an expensive video system installed

Have you tried a home office to home office conference call with someone in India? Decent audio is problematic, never mind video. Due to timezone differences, it’s not even practical to get everyone into a room with high end equipment – unless you consider it employee friendly to ask one set to be at work at 9 PM.

We are already minimizing business travel about as much as possible, based on cost. Minimizing it further will only lead to more miscommunication.

34

Jeff 12.15.07 at 11:41 pm

Ocean shipping (which often uses very dirty fuel) is a major source of pollution. Perhaps there’s a future in sailing ships.

35

Syd Webb 12.16.07 at 12:05 am

Brettt Bellmore wrote at #25:

We have a saying where I work; “If we could do without you for that long, we could do without you.”

A timely reminder that not everywhere in the world is like Australia. Here we have cycles in the business that allow people to take holidays (vacations) in quieter times. We have multiskilled employees so I can cover for my boss when she’s on leave and one of my subordinate’s can cover for me.

I can imagine a small business, staffed by distinct specialists, that operates 52 weeks of the year at full pace. (I’m also seeing a lot of buurnout.) What I’m not seeing about this model is that it is typically, and uniquely, American.

36

Michael Connolly 12.16.07 at 1:32 am

Re: #1 (Improbable’s question about the price of air travel) – My first round trip flight from Washington, DC to Brussels, in March 1972 – an excursion fare – was $400. A gift from my grandmother to start me on a semester abroad. That’s why I remember. Someone else will have to convert that to 2007 dollars.

37

Matt McIrvin 12.16.07 at 1:46 am

I think a lot of businesses in the US actually could stand to let people take longer vacations. It’s just that this isn’t the cultural norm.

There are odd things that happen in the software industry. Professionals in the industry often get anywhere from 10 to 20 nominal vacation days a year based on seniority, and rules vary as to how much of this leave you can carry over to the next year. But it’s often not possible to take all that time off due to job demands, or it is possible but people don’t do it out of some misplaced sense of pride.

Sometimes there actually are people who do more or less as Quiggin suggests, but by accident–they see life as a series of crunch periods in which they’re not able to take any time off, and after two or three years of little or no vacation at all (with, perhaps, deleterious effects on sanity), the Human Resources department tells them to take some time off or lose it, so they go on a month-long vacation.

38

Matt McIrvin 12.16.07 at 1:48 am

…Also, by the way, it’s quite common here to lump vacation and paid sick leave together in a single category, so that if you stay home sick, that cuts into the vacation you can take later.

39

Matt McIrvin 12.16.07 at 1:55 am

With international teleconferencing, some of it still goes over satellite links, with a corresponding speed-of-light delay that is long enough to derail a conversation. That just compounds the difficulties associated with bad audio quality and language differences.

But all these things, except perhaps for language differences (which are also a problem with travel), can be addressed by better technology–the speed-of-light delay by ground links, where the total distance is much shorter.

Time-zone differences are a more difficult problem, but, then, they cause serious trouble for jet travelers too, unless they concentrate their trips into longer stays (which would also burn less jet fuel).

40

John Quiggin 12.16.07 at 1:57 am

I’ll flag that I intend a post on business travel before too long.

41

Quo Vadis 12.16.07 at 2:59 am

@James Robertson #34

I don’t know what your business context is, but if you look further outside the box, you might find more opportunities.

In order to take full advantage of new technologies, businesses have to adapt their business processes to the technologies, rather than simply trying to adapt the technologies to existing processes. Look at how far individuals have adapted their own shopping, banking and socializing processes to take advantage of new technologies.

For example:

Twenty years ago, a software development project would begin with months and even years of meetings between developers, users, budget managers and others to hash out a very comprehensive and extremely detailed specification of exactly what the system should do. The developers would then implement the specification and deliver the final product (with any luck!).

Since that time there has been an evolution toward a much more dynamic, iterative process where the users generate a high level description of the system, or a part of the system and the developers deliver a prototype for the users to review and suggest changes. This evolution required a complete re-think of how software projects are planned and budgeted. While many managers were (and some still are) uncomfortable with the open-endedness of the process, this iterative, non-verbal communication process has not only reduced the ‘face-time’ requirements, but has proven to be more effective resulting in better results and fewer failed projects.

And how about changing expectations? Does a salesperson really have to show up once a month to take a customer to lunch to demonstrate how important that customer’s business is?

42

James Robertson 12.16.07 at 3:32 am

We follow a fairly agile development process – which, interestingly enough, requires more and better contact between people who work together. When those people are geographically dispersed, regular travel is simply necessary. Bear in mind, in this context, “regular” is a few times per year.

As to changing expectations, customers do expect to be visited regularly, and ignoring that leads to lower sales. You can argue that it shouldn’t be that way, but it just is that way.

43

SG 12.16.07 at 5:52 am

It seems some Americans think the world will end if they have to take vacations as long as are routine in the UK, Europe and Australia? Wierd.

I heard that the airlines were considering a new seating configuration to ease the problem of reclining seats in economy, teh configuration being face-to-face, so my seat faces forward and teh person next to me faces back – a zigzag arrangement. Apparently this fits more people in and gives more space, because there is more legroom so reclining is easier. I read this a year ago in the Sydney Morning Herald.

As regards business travel, here in Japan business travel is very common but it is largely done by Shinkansen (Bullet Train). It costs about the same as the plane, maybe a little less, takes about twice as long but is easier to book, requires no early arrivals or check ins, and delivers you into the centre of the city. It’s also much more comfortable. So overall it ends up being competitive with air travel for all but the longest trips. I don’t see why that couldn’t be used by other big polluting countries (e.g. the US), at least in their densely populated regions.

(Also interestingly the Japanese have already introduced ruthless efficiency mechanisms into their businesses, including for example having all the lights off in the halls at my university, so it is pitch black after 4pm, and only using half the lifts. They are remarkably easy to get used to).

44

brooksfoe 12.16.07 at 7:07 am

All of the figures cited involve planes flying at 70% of capacity; most assume 90% of capacity or higher. This is contrasted to fuel consumption for cars with just one occupant. “The average jet plane now uses around 4.8 l/100 km per passenger – just a little worse than a Prius with no passengers”; “Boeing’s 747-8 uses 3.7 l/100kms per passenger when operating at 70 per cent of capacity.”

Obviously, put just one passenger besides the driver in the average Prius, and you achieve a fuel efficiency no aircraft on the horizon could ever match. Meanwhile, in the real world and on real routes, there will continue to be some aircraft flying half empty. Some 747-8’s will be getting a lot less than 3.7 l/100 km, whereas it’s impossible for a Prius to get less than 4.4 l/100 km because it’s impossible for a car to travel with less than one person in it.

45

Bruce Baugh 12.16.07 at 7:22 am

SG: News flash! Too many people in positions of power in American society have really screwed-up views about wellness! And too many others buy into their lies! I’m sure this is a shock to you. :)

46

James Robertson 12.16.07 at 7:23 am

And the Prius is impractical for a trip from where I live (Maryland) to California. I’m simply not going to trade a few hours flying for days of driving.

As to additional passengers – it gets complicated when you don’t have a mass of people traveling from point A to point B, and then you additionally mix in all of those people’s issues with children: day care, sports, other activities – lining up car pooling is a very non-trivial task. My wife and I tried it back in the late 80’s, before we (or the people involved) had kids. It was more trouble than it was worth, because our formerly flexible work schedules suddenly became inflexible.

You simply aren’t going to change driving habits given the current layout of the US, and it’s not suddenly going to become centralized, either. We have what we have, and wishing isn’t going to change it.

47

richard 12.16.07 at 12:59 pm

On the US vacation issue: Sometimes there actually are people who do more or less as Quiggin suggests, but by accident

Indeed. Quite a few people work on Quiggin’s model of widely-spaced, longer periods of downtime, especially in the software and entertainment industries. They get taken on for projects that are in a crunch, stay for 1 or 2 years until the project’s done, then quit through burnout or get thrown out. As an added plus, they usually aren’t able to go on extended foreign vacations between jobs because they’re scrambling around looking for another gig to pay the bills. If only we could move more of the economy onto this footing, there’d be a significant drop in air travel.

48

Tracy W 12.16.07 at 2:00 pm

And we have to expect that the effect on business travel would be equally strong. I would say that most business (and academic) travel is pretty wasteful as it is, but the effects on the hotel and restaurant businesses from shrinkage also would be severe.

On the other hand, presumably the people who would have been flying otherwise, will stay at home and either spend their money on other things or invest it.

There would be shrinkage in hotels and restaurants, but gains somewhere else.

49

Barry 12.16.07 at 2:32 pm

“It seems some Americans think the world will end if they have to take vacations as long as are routine in the UK, Europe and Australia? Wierd.”

No, weird is that they’re *proud* of it.
Also resentful of others who don’t have to do that, but that’s quite normal.

50

Barry 12.16.07 at 2:34 pm

James, in #34: most of what you say is covered by ‘telecommunications is getting better, year by year’. Your point about time zone differences is actually an anti-point – business travel deals with it by sandwiching the time change between two 12-24 hour stess periods. Which is what I’d expect to *enhance* the time stress, not reduce it.

51

James Robertson 12.16.07 at 3:20 pm

Barry – You try to explain to people on the other side of the planet how it’s more friendly for them if they head into the office at night (where the god comms equipment is), instead of you heading over there to see them.

Then try selling your management on the idea that they should come in at 9 PM, or midnight. Good luck with that :)

52

hhoran 12.16.07 at 4:13 pm

Your analysis is based on a profound ignorance/indifference to basic transport economics. You talk about reasonable step function changes (achieving pax per auto rates of 1990) but then assume you shift all airline traffic into super-high density A380s/787s. This is like assuming that every commuter in New York achieves the fuel/carbon efficiency of the IRT at rush hour. There are only about 50 airline routes in America with more than 800 pax per day. Thus your plan assumes shutting down the entire national air service network, and limiting everyone on these 50 routes to 1 or 2 flights a day. Which of course would be run by a state monopoly, since there isn’t enough scope for workable competition, and you’ve destroyed all of the network economics. IATA’s “easy 12%” from Air Traffic Control is strictly from Europe where huge allocations for military airspace and a crazy patchwork of national ATC system create problems. Totally inapplicable elsewhere, and European solutions are only “easy” once you eliminate all the national governments and their militaries. In America the only substitute for higher priced aviation, is driving, and you’ve totally ignored these negative impacts. The macro economy-wide shifts that drove the growth of long-distance air travel (increased trade and labor mobility, competition/technology allowing businesses to serve much wider markets, leisure industry changes making Vegas/Orlando competitive with family trips to the local lake) are 90% driven by productivity gains. The growth of intra-metropolitan highway travel reflect consumer preferences but were heavily influenced by tax/regulatory subsidies (biases favoring new, lower-density home construction, highway construction, competition between municipalities on taxes and schools, among many others). Disproportionately attacking aviation’s carbon issues is also an attack on fundamental parts of the industrial base that are highly efficient, and have no ready way to adjust. Moving residential densities and commuting patterns back to 1990 levels would also involve serious dislocations and costs, but would have a much, much smaller impact on national income and productivity. Zamphir has already explained why Rowland’s aircraft fuel efficiency numbers were totally inappropriate. Yes, the cost of flying will increase under any hypothetical solution, but I didn’t see a single factual/economic assumption in the post that would survive serious scrutiny.

53

Slocum 12.16.07 at 5:28 pm

I work in this arena now, and I can tell you – your theory about this is just wrong. Lots of companies are trying to minimize the number of trips required, but they have found that you simply cannot eliminate them all.

I’ve been working in virtual software development teams for more than a decade. Face-to-face meetings are already pretty rare (on the order of once or twice a year). I do find it helpful to have met people at least once, but beyond that, we don’t even bother with video conferencing — voice and shared presentations seems to be more than sufficient with people you know. And, of course, we use lots of email.

As for time zones — I’d much rather work early or late occasionally for a teleconference than fly to the other side of the globe and back. And for any given two locations on the planet, there are plenty of hours of overlap (assuming 16 hours awake and 8 asleep, the worst case is still 8 waking hours overlap every day). So you schedule a weekly 6AM/6PM phone meeting. Big deal. And that’s worst case — with time differences less than that you can schedule meetings during work hours on both ends.

54

James Robertson 12.16.07 at 6:44 pm

slocum: Assuming that what anecdotally works for you will work for everyone else is not realistic, and face to face meetings make it much easier to avoid unintentional disagreements.

55

Barry 12.16.07 at 7:37 pm

James, you’re playing games here – claiming general principles, but claiming ‘anecdote’ on others.

“Barry – You try to explain to people on the other side of the planet how it’s more friendly for them if they head into the office at night (where the god comms equipment is), instead of you heading over there to see them.”

At this point, I’m going to stop being ‘politically correct’, and start being honest:

If you are trying to sell something to them, and they are in a position of power, then *you* are going to head into the office at night. If vice versa, then vice versa. Why don’t you realize this?

“Then try selling your management on the idea that they should come in at 9 PM, or midnight. Good luck with that :)”

‘Joe, you wanna keep the business, you come in for some midnight conference calls. Otherwise, you spend 12-24 hours travelling, and meet them face to face, at midnight your biological time. And then spend 12-24 hours travelling back. Oh, you don’t get any lighter workload because you’re on the road.’

Which do you think that Joe will prefer?

56

Quo Vadis 12.17.07 at 12:36 am

@James Robertson

I understand completely all of your points, in fact I’m sure that most managers the world over would echo them. Change is risky and usually results in costly mistakes in the near term. But we are talking here about change that may be imposed on businesses by external factors.

Ignoring the climatic issues, it seems likely that there will be economic and regulatory changes that will effect the competitive playing field. Businesses will adapt sooner or later, and those that adapt sooner will come out ahead.

Adapting sooner means exploring process changes and technologies now, on a small scale rather than trying to catch up with your competitors after your business has fallen behind.

Frankly, I think this is a good place for government to take a leading role. Government and business share many basic processes and much that could be learned from government efforts would be directly applicable to business.

57

ajay 12.17.07 at 12:03 pm

If it’s relatively easy to get the whole population to change its habits as John suggests, why not make a few adjustments to the national diet, restricting early intake of protein to a healthier level?

Can I have a pony, too?

No, ponies are high-protein. Have some lettuce.

58

GreatZamfir 12.17.07 at 1:31 pm

38:

What about this issue of fuel-consumption improvements in new models, per-passenger versus the raw figures? Are the raw figures corporate secrets? If they were available might using them be semi-fatal to the overall argument here?

Well, detailed performance figures of yet-unbuild aircrfat, mainly its weight and air resistance, are not only secret, they are not even known for sure until the aircraft is ready and flying. But Boeing has to sell its 787 anyway, so they promise numbers to the airliners. If Boeing doesn’t make those numbers, it will pay a fine, if they improve on it they get a bonus, but they would have made more if they had promised the better numbers in the first place. So Boeing has a good incentive to show realistic figures to airliners. Those numbers are still confidential, but the overall idea seems to be that it will burn up to 20% less fuel than its very similar predecessor 767. Airliners will use part of that effiency to fly longer routes non-stop, and this increases fuel burn per mile again, so we can expect roughly 15% decrease in actual fuel burn per paxkilometer, compared to an aircraft with a 1980’s structure and 1990’s engines. This improvement is considered so big by airliners that the 787 is sold-out for the next 7 years or so.

I think this is pretty fatal to the argument. Technology is still improving , and there are enough new ideas for it to keep improving for many years to come. But there is absolutely no reason to assume a 50% reduction in fuel burn per passenger kilometer within the the next few decades.

People have often used improvements since the early jet aircraft to show that technology improvements are rapidly improving efficiency. But this is more a measure of the enormous inefficiency of early jet aircraft. In fact, the next generation of jetliners will be the first to use less fuel per paxkilometer than a 1950s propellor-driven Lockheed constellation (although, of course, at much higher speed and a lot safer). There is no reason to assume similar improvements in the future unless people will accept lower speeds and more stops en route, and even then improvements may less than expected.

59

John Quiggin 12.17.07 at 9:25 pm

“Airliners will use part of that effiency to fly longer routes non-stop, and this increases fuel burn per mile again, “

Can you explain this? It seems obvious to me that the opposite should be true – flying non-stop from NY to LA must use less fuel than landing in, and taking off from, Atlanta en route.

Obviously, there’s a load factor problem which is why airlines go for hub-and-spoke, but I assume that’s not your point. Since load factors are highly responsive to price incentives, my argument assumes that they will be pretty close to 100 per cent, at least for the kinds of journeys typically taken by tourists.

60

John Quiggin 12.17.07 at 9:53 pm

hhoran, your argument appears to begin from the premise that I’m proposing a set of policies that would apply only to air travel. Obviously (well I thought obviously) that’s not the case – I’m looking at the question of what kinds of adjustment would be necessary to get to a 75 per cent reduction in emissions across the board, given the price incentives that would push people in this direction. So to the extent that there is substitution to other modes, it will be away from both planes and private cars, and towards buses and trains.

For domestic US travel, it seems pretty clear that B787/A350 planes are likely to dominate most routes, so it would be silly to assume 800 passengers per plane. But this post was about long-haul tourist travel, not about domestic US travel.

61

John Quiggin 12.17.07 at 10:52 pm

As a modest reality check on the 50 per cent number, I found this statement from Lufthansa

Since 1991, for instance, we have increasingly succeeded in decoupling our transportation services from effects on the environment. Over this period our transport volume has more than doubled, yet our kerosene consumption has risen by only around 50 per cent. We intend to continue this trend. On average, aircraft ordered in 2006 will run on about 33 per cent less fuel than previous models

Given that I’m looking several decades into the future, 50 per cent doesn’t seem outlandish. And, I imagine that plenty of the low-hanging fruit Lufthansa picked before 2006 remains available to airlines that won’t pay attention to the problem until prices force them to do so.

62

Great Zamfir 12.18.07 at 10:37 am

60.

“Airliners will use part of that effiency to fly longer routes non-stop, and this increases fuel burn per mile again, ”

Can you explain this? It seems obvious to me that the opposite should be true – flying non-stop from NY to LA must use less fuel than landing in, and taking off from, Atlanta en route.

You happen to be right about LA- NY. But for really long-distance flight, you have to bring the fuel for the last part with you on the first part. For transpacific flight, over 40% of take-off weight is fuel ( meaning almost as much the entire aircraft would weigh empty), and this damages fuel economy on the first part. The result is a sort of ‘Laffer curve’ ;) , where for short distances fuel economy improves with distance because take-off is a smaller part of the total consumption, but beyond a certain distance fuel economy deteriorates as the fuel-carry penalty becomes big.

If you look at curves, fuel use per kilometer is best around 4000-5000 kilometer,close to LA-NY and close to the design range of the 767. The 787 is designed more for 9000 kilometer trips, and it will probably get permission to fly longer over oceans.

But rereading my post, I think I stressed this point too much. I used it more as an example how increased efficiency can eat its own gains, but that would be more a topic for your elasticity post.

63

John Quiggin 12.18.07 at 11:14 am

Thanks, zamfir, this is very helpful. I plan to come back soon with more, and will look forward to your contributions.

BTW, I edited your comment to remove repetition and accidentally cut the para about Lufthansa. Sorry about that.

64

Great Zamfir 12.18.07 at 11:22 am

As to the 33% cited by Lufthansa, I can only guess how they made this up. I suspect they compared the figures for their new long-range, big aircraft with their fleet average including many small, short-range aircraft. And of course they will not replace those with the big ones.


This is a link to Boeing’s 787 site
. It claims 20% percent improvement in fuel burn over the current generation of similar-sized aircraft ( that’s 767, introduced in mid-80s and A330 from early 90s). I would say this is pretty much a high limit to the real improvement, since it is generated by Boeing’s marketing department. And as I mentioned before, airliners are jumping to the chance to get these improvements.

Another interesting link. This is a small NLR (Dutch Aerospace Laboratory) report about trends in fuel burn. Their conclusions are that the IPCC is overestimating the efficiency increase in the past, and that efficiency growth is slowing. They estimate a 55% percent decrease in fuel burn from the 707, the first successful jet from around 1960, to present jets, but the slowdown of efficiency growth makes a similar improvement in the next 40 to 50 years very unlikely.

Don’t get me wrong, I mostly agree with your thesis that we can reduce CO2 emissions without severely damaging life as we know and value it. But I think that here you are putting too much hope on technology improvements to do the heavy lifting. Especially in aircraft, where fuel burn has already been the driver behind technology for many decades, and the simple improvements are already made.

I have seen some reports that did try to estimate what should be done to reduce CO2 emissions by 50% , and they seem to conclude that it will require every not entirely unrealistic technology people have dreamed up, plus a shift to flying slower and lower ( lower actually hurts fuel burn, but apparently CO2 does less damage at lower altitudes).

Here is a Boeing research project incorporating just a few of those ideas. Even if you can’t understand of all the details, just look at the pictures to see the enormous difference from present aircraft. And then realize that developing a normal new aircraft costs already between 10 and 20 billion dollars.

65

richard 12.18.07 at 4:17 pm

I think I’m still not getting this: you’re suggesting raising taxes on air travel to the point where most people who travel once a year are now persuaded to cut that in half? What level is that, exactly?

It seems to me that lower income people would be prevented from flying at all, there would be a social stratum that would fly with reduced frequency as you suggest, and upper strata would be largely unaffected. Advantages of this would include overall reduced flight volume and the ejection of the hoi polloi from your comfy little tourist spot in the Bahamas, or Thailand or wherever. Also, I imagine, a radical reduction in tourism-related income for the Bahamians, concentration of services on the wealthy minority that is capable of frequent foreign travel, and the return of free champagne aboard for the reinstated privileged jet set.

I can see that something like a per-mile tax would change my own vacationing habits strongly: coming from a place with a relatively high median income and a strong currency, when I’m planning a vacation I find there’s often a trade-off between flight cost and food/lodging costs: I could fly cheaply within Europe or within North America, but pay a high cost each day, or I could drop more on a flight to India and make up the difference in my time there. With your suggested tax hike I’d just stop thinking about going to India or China or anywhere like that, but I’d still want to go on frequent trips over a shorter distance. Sadly, with my parents being across the Atlantic and my wife’s being in South America, I guess we’d just never see them any more. And I imagine that for those families in India or China who have relatives in Europe or North America, they’d just go back to the old model where they have to choose between permanent separation and eventual migration, right?

66

Quo Vadis 12.18.07 at 5:13 pm

One point that hasn’t been made here is how much impact speed has on the efficiency of aircraft. The thrust required varies with the square of speed, so it takes roughly 4X the thrust (and therefore fuel) to fly 2X the speed. As fuel costs climb, the consumer’s trade-off between flight time and ticket cost would tend toward longer flight times. At what point do the airlines and aircraft manufacturers decide spend the R&D money to develop large aircraft optimized for 300 mph?

67

GreatZamfir 12.18.07 at 7:36 pm

@ quo vadis: This is definitely true, lower speed might be the best way to reduce fuel burn, but it would not happen as fast your quadratic formula suggest. Drag is roughly proportional to the square of speed for a given plane or vehicle, but that’s not true when comparing different aircraft.

Roughly speaking, for a given aircraft weight you need smaller wings the faster you fly, and this reduces drag just as much as the higher speed produces. So the drag associated with the fuselage is the only thing that goes up with speed.

On top of that, keeping an aircraft airborne produces a drag that actually rises when speed goes down (which is more or less why aircraft can’t hover). So decreasing speed can only go so far before drag goes up again. The optimum here depends more or less on weight, so it makes sense for small craft to fly slow, but not for big ones (birds fly even slower). In fact, current long-range airliners have weight-to-drag ratios unmatched by most slower aircraft.

The main reason aircraft might benefit from lower speeds is that currently a lot of aerodynamic trade-offs are needed to postpone and diminish speed-of-sound effects ( the MSc thesis I am working on is about this, for example :-) ). If we were to fly slower we would have more freedom to design a better aerodynamic shape.

Luckily, we have a beautiful example of the efficiency gains that could be achieved if someone spends all available design effort on a big plane with minimum drag without need for speed. The Global Hawk, a very large unmanned reconnaissance plane has a optimal weight-to-drag of 33 at a speed of 400 mph (presumably the optimum, sice the aircraft flies in circles), compared to optimum 19 for current airliners. It’s unlikely we could reproduce that 33 in an aircraft with a large fuselage and higher weight, but perhaps 25 or so might well be possible. That’s 20% gain from flying slower and redesigning.

68

John Quiggin 12.18.07 at 7:59 pm

Richard the point of the post was that, although at first sight it might seem as if the consequences of higher costs for aviation-related CO2 emissions would be dramatic (no flights at all for the poor, closing down places like the Bahamas), actually most of the adjustments would be pretty modest.

For example, people going to the Bahamas or crossing the Atlantic to visit family would respond to higher travel costs by going less frequently and staying longer. The net impact on time spent at the destination would be small.

For people who don’t have a strong desire for a particular destination, the implication, as you say, is to have your holidays closer and spend more when you get there. Again, the net impact on standards of living is modest.

Obviously, there are some particular social strutures that are impediments to this kind of adjustment, like short holidays in the US, discussed above. I’ll discuss in subsequent posts why this means we need to look at things other than prices. But prices will do most of the work.

Comments on this entry are closed.