Marginal Economics Fail

How much more carbon does filling a marginal open seat on a bus produce vs. filling a marginal open seat on an airplane.  My guess is the answer rounds to zero even with a lot of decimal places.

Story here.


  1. randian:

    Not only is that an economics failure, it's a pollution one. A modern automobile produces far less CO, NOx, and particulates than a bus or airplane do.

  2. Matthew Slyfield:

    Yes, but for calculations for attributing a share to individual riders, you have to calculate on a passenger mile basis. Buses and commercial passenger aircraft carry a lot more people than a car.

  3. randian:

    True, but essentially all pollution emitted by a modern car is emitted when cold. When warm, a ULEV produces basically zero emissions. No bus or aircraft comes close, on a gross or passenger-mile basis.

  4. Matthew Slyfield:

    Can you cite any evidence that there are enough ULEVs acutally in use in the United States to even matter?

  5. slocum:

    To be fair, the main reduction in his carbon footprint will not come from switching from plane to bus, it will come from the big reduction in miles traveled (he won't be crossing oceans by bus).

  6. Mole1:

    A bus gets > 200 passenger miles per gallon, a modern plane ~100. Your criticism is misplaced. If each individual acts to minimize his personal emissions by optimizing his means of transportation toward that goal, the market will rebalance the number of trips made with each mode of transportation appropriately. It makes no sense to argue that because his first trip has negligible effect, he shouldn't bother making a change in his travel habits. His decision has an effect on the market.

  7. herdgadfly:

    We have here the perfect incomplete economic analysis. Handicapping any of the modes based upon carbon footprint is silly because CO2 is not a pollutant. Then we get to dismissing automobiles because the trip would cost 56 cents per mile - but it does not. Decision making for a week or so of travel requires you to consider variable costs only - the cost of gasoline used - which works out to be only $238 or about 14 cents per mile.

    So when I get past the self-imposed guilt trip of the greenies, there is but one sensible way to get from Madison to Atlanta and back - drive! As for the WiFi consideration - you need it mostly because transit modes take too long unless you fly. If you need the connection for your work, then you likely have purchased internet from your cellphone provider. Otherwise it is safer not to be distracted by internet service while on the road.

  8. Rick C:

    When Beijing looks the way it does, what difference does it make?

  9. Matthew Slyfield:

    None, if there aren't enough ULEVs in actual operation to have any impact. That's the point.

  10. Michael:

    Mole1's answer is correct. Every time one purchases a ticket, that information is fed into an algorithm for determining if there should be another flight or another bus. The probability that your ticket is the one that triggers a new flight or bus is small but not zero and the impact is huge in either case. The average cost per passenger mile is a reasonable way of thinking about the expected value of the marginal (not average) impact of traveling by one mode over another mode.

  11. Griffin3:

    This is a good thing. Mr. Holthias gets 2 days (round trip) less effective work done every time he attends a conference in Atlanta. Don't even kid me that you can get as much work done on a bus as in a real work environment, unless your work consists of writing poorly researched diatribes and massaging data to show scary, non-real trends in global warming/cooling/othering. And sending self-important tweets about how much you are saving the world.

    All of this gives a 2-day competitive advantage to the scientists and engineers who are actually working on a solution to the problem, like finding ways to run airplanes more efficiently on less fuel. How to increase the speed and efficiency of automobiles such that they rival airplanes in speed. Etc. So, let us all encourage Eric in his willingness to trade 23 hours of his life for 87 pounds of CO2 (each way) ... it clears the way for working people to make more progress towards a real solution.

  12. Rick C:

    No, you missed my point. How many ULEVS in the West does it take to balance out China's dumping of pollution. You're looking for your lost quarter under the streetlight.

  13. randian:

    Doesn't matter how many ULEVs we have it won't offset China. To Matthew's point, the difference between LEVs and ULEVs is trivial. Replacing the entire existing fleet of LEVs with ULEVs only makes a difference in the mind of an EPA bureaucrat needing to justify his job, and in the minds of anti-car zealots. It will make no difference in real pollution, since auto pollution has long been a solved problem.

  14. FelineCannonball:

    On top of that, the load factor for domestic flights is about 84 percent and 50 percent for greyhound. For daylight flights between decent sized non-hub towns occupancy is mostly 100 percent. In other words airlines are much more responsive to demand.

    The idea of a marginal empty seat on a plane gave me flashbacks to the 1990s.

  15. Rick C:

    Yes, that was my entire point, randian. If pollution is a problem, and you want to solve it, you need to solve it in China, India, Russia, etc., not fiddle around the margins in the US. I suspect if we changed ALL cars in the US to ULEVs it wouldn't make much difference to global pollution, when the Beijing skyline looks like it does. So to wrench this back on topic, who cares that the guy in the linked article has vowed never to fly again?

  16. m1shu:

    You're forgetting the number of miles a bus route from Milwaukee to Atlanta is significantly more than a direct flight from MKE to ATL.

  17. Matthew Slyfield:


    My point was that ULEVs are irrelevant. Sorry, I'm not the one looking for a lost quarter under a streetlight or anywhere else. And your original point about China is irrelevant to the thread.

  18. marque2:

    Busses average ridership is so low that they generally pollute more. Yes they seem full during rush hour - but they ride empty the rest of the day and weekends.

    Another mistake - since you have a dedicatednbus driver - you have to include all the pollution he or she produces as well.

  19. Matthew Slyfield:

    I don't disagree with that, but a proper per passenger mile analysis would use actual average ridership, not capacity. However, that is irrelevant to the validity of randian's claim that ULEV's make cars cleaner.

  20. Matthew Slyfield:

    "To Matthew's point, the difference between LEVs and ULEVs is trivial."

    What percentage of the US auto fleet (all vehicles in use, not percent of current year models) qualify as LEVs? My guess would be that the percentage is quite low.

  21. Matthew Slyfield:

    The OP is about the relative carbon footprint of different modes of transportation, not about solving the global pollution issue. Your point is not relevant to that conversation.

  22. randian:

    LEV has been in effect since 2004. What percentage of the fleet that constitutes I have no idea. Nearly all small cars qualify as ULEVs these days. Even large cars like Lexus LS460s are ULEVs.

  23. Rick C:

    From Slate: "Since the implementation of the Kyoto Protocol in 1990, global emissions have actually risen by 61 percent, reaching a new record high in 2013." He was reducing his own carbon footprint by driving, to make a dent in glowball wormening. This is searching under the streetlight. A far more effective way would be to convince the Chinese and Indians to cut back on their pollution. Rich white liberals don't want to try to do that, though, they'd rather limit Westerners' ability to have carbon footprints.

    You go on missing the forest for the trees, though, if that makes you feel better.

  24. Rick C:

    Why are ULEVs irrelevant? Let's see if you can figure out why I'm asking.

    Oh noes, topic drift!

  25. Matthew Slyfield:

    You are correct, but it still isn't relevant to the issue under discussion. Nobody is missing anything except for you.

  26. Matthew Slyfield:

    I know why you are asking, but your reasons are not relevant to the topic under discussion. ULEVs and LEVs in general are not relevant because there aren't enough of them to effect the average per passenger mile CO2 emissions of the US auto fleet so they won't affect a carbon footprint comparison between modes of transportation which is the issue under discussion.

    You however, want to make the issue about smog in China and India, which has nothing to do with CO2 or global warming. Yes, those are real issues and arguably more important issues than what we are discussing here, but they are not what we are discussing here.

  27. randian:

    It wouldn't matter if all vehicles were ULEVs, LEV/ULEV aren't CO2 standards. Gas mileage standards are CO2 standards, since CO2 output is proportional to weight/load.