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Pretty clear case of this: http://en.wikipedia.org/wiki/Tragedy_of_the_commons http://en.wikipedia.org/wiki/Tragedy_of_the_commons The shared resource in this

Pretty clear case of this: http://en.wikipedia.org/wiki/Tragedy_of_the_commons http://en.wikipedia.org/wiki/Tragedy_of_the_commons The shared resource in this case is traffic capacity. It's proved ineffective to regulate traffic by making cars expensive in this market. That's because cars are not profit centers for people -- they give mostly intangible benefits (increased comfort, status, etc). Taxis on the other hand are cars that are used for profit and therefore will respond efficiently to regulation (if that regulation increases capital or operating costs).

thaumasiotes 14y ago
In a classic tragedy of the commons, you might have a common field, on which sheep graze. Everyone takes their sheep there, the sheep deplete the grass, and after this process has been in place for a while, the total capacity of the common field to support sheep is lower than it might be otherwise. That diminished level of sheep capacity is the "tragedy". What's your model here? That if there were fewer cars on the roads of Bangkok, it would be able to support more cars? What would there be more of, in total, if you confiscated a bunch of people's cars? Would you advocate banning most people from a popular public beach on the grounds of overcrowding? Would you justify that as preventing a "tragedy of the commons"?
- Kliment 14y ago
  More fresh air. Less dust. Less noise. Shorter transport times for everyone. Congested traffic makes everyone's trip longer and less convenient. Any individual gains from using a car as opposed to not using a car as long as the traffic is not congested. Too many individuals doing what personally benefits them make it worse for everyone. This is the definition of tragedy of the commons. In the sheep example, every shepherd benefits from using the field, but if too many sheep use the field, it's ruined and noone can use it. Same with congested traffic.
- Arelius 14y ago
  I couldn't say for sure since I haven't studied it properly, but I think due to traffic, at some point we have a lower capacity to move people in a timely fashion. So perhaps the thing that there could be more of, in total, is "amount of people moved per unit time". Again, I just hopped into here, and haven't much evidence to back that up, but it's the sort of thing that seems likely.
  - mbenjaminsmith 14y ago
    Yeah it's called a traffic jam. As the total number of cars on the road per unit of distance increases, the speed at which those cars can travel decreases. It's not linear of course but, well, I think you get the picture.
    - mikeash 14y ago
      As you add cars to a road, the throughput in terms of the number of people or cars per minute first increases. This should be pretty obvious: as you add cars to a nearly empty road, more people use it, but they all go just as fast as before. As you continue to add cars, you reach a point where cars start to slow down, but throughput continues to go up. Once you reach a certain point, people begin to drive slower due to congestion. But at low levels, this is offset by the additional number of people using the road, resulting in greater total throughput. Past that point, you reach another point where adding more cars does not increase throughput, as the added cars are balanced by the slowing of traffic as a whole. Beyond this point, adding more cars reduces the throughput of the road. Take this to the extreme, and you have a giant parking lot with people gradually inching forward, and people/cars per minute excruciatingly low. No sources, but I'd think this is all fairly obvious.
      - thaumasiotes 14y ago
        This is fair. I would submit that there's a strong argument that, when the total supply of sheep goes up, everyone benefits. I don't think that's true of road throughput; that just benefits the people who are still on the road after you've put up the barrier to entry. I don't see that there's any sort of failure involved in the phenomenon of traffic jams -- I've "happily" sat in stop-and-stop traffic because it's still better than my alternatives. Participate and pay the cost of annoyance due to congestion, or don't and don't. You're on thin ground saying "you need to get off the road, so that it will function better for me".
        mikeash 14y ago
        When everybody tries to crowd onto the highway, everybody slows down. Beyond a certain point, throttling usage actually makes everybody get to their destination faster. Imagine a roadway with some kind of nasty merge which gets severely jammed up if there are too many cars. If ten cars all try to go through at once, everybody could be stuck for quite a while. If you throttle them so they go through one by one, everyone gets to their destination faster. The same thing can apply to real roads on a larger scale.
- mbenjaminsmith 14y ago
  "What would there be more of, in total, if you confiscated a bunch of people's cars?" Road. Fewer cars on the road would mean a more constant speed for the cars on the road. "Would you advocate banning most people from a popular public beach on the grounds of overcrowding?" You generally don't have to. Since the benefits of going to the beach are relatively low, people more efficiently self-regulate their usage. That is, if a beach is too crowded to put down a towel, you'll probably leave. That's not the case with taxis. As long as buying taxies and renting them out is profitable, taxi operators will continue to do so. To make things worse, the profitability of driving a taxi is only indirectly related to the profitability of renting that taxi out. The cost of rental is relatively stable while the money made by the driver varies considerably. The drivers absorb short-term (even medium-term) fluctuations in the market.
- gcb 14y ago
  More people moving. Car is not the goal. There are other means to move people way more efficient.
  - thaumasiotes 14y ago
    Be careful. It's very, very hard to demonstrate that other methods of transportation are "more efficient" than cars, even in heavy traffic.

thaumasiotes 14y ago

In a classic tragedy of the commons, you might have a common field, on which sheep graze. Everyone takes their sheep there, the sheep deplete the grass, and after this process has been in place for a while, the total capacity of the common field to support sheep is lower than it might be otherwise. That diminished level of sheep capacity is the "tragedy". What's your model here? That if there were fewer cars on the roads of Bangkok, it would be able to support more cars? What would there be more of, in total, if you confiscated a bunch of people's cars? Would you advocate banning most people from a popular public beach on the grounds of overcrowding? Would you justify that as preventing a "tragedy of the commons"?

Kliment 14y ago
More fresh air. Less dust. Less noise. Shorter transport times for everyone. Congested traffic makes everyone's trip longer and less convenient. Any individual gains from using a car as opposed to not using a car as long as the traffic is not congested. Too many individuals doing what personally benefits them make it worse for everyone. This is the definition of tragedy of the commons. In the sheep example, every shepherd benefits from using the field, but if too many sheep use the field, it's ruined and noone can use it. Same with congested traffic.
Arelius 14y ago
I couldn't say for sure since I haven't studied it properly, but I think due to traffic, at some point we have a lower capacity to move people in a timely fashion. So perhaps the thing that there could be more of, in total, is "amount of people moved per unit time". Again, I just hopped into here, and haven't much evidence to back that up, but it's the sort of thing that seems likely.
- mbenjaminsmith 14y ago
  Yeah it's called a traffic jam. As the total number of cars on the road per unit of distance increases, the speed at which those cars can travel decreases. It's not linear of course but, well, I think you get the picture.
  - mikeash 14y ago
    As you add cars to a road, the throughput in terms of the number of people or cars per minute first increases. This should be pretty obvious: as you add cars to a nearly empty road, more people use it, but they all go just as fast as before. As you continue to add cars, you reach a point where cars start to slow down, but throughput continues to go up. Once you reach a certain point, people begin to drive slower due to congestion. But at low levels, this is offset by the additional number of people using the road, resulting in greater total throughput. Past that point, you reach another point where adding more cars does not increase throughput, as the added cars are balanced by the slowing of traffic as a whole. Beyond this point, adding more cars reduces the throughput of the road. Take this to the extreme, and you have a giant parking lot with people gradually inching forward, and people/cars per minute excruciatingly low. No sources, but I'd think this is all fairly obvious.
    - thaumasiotes 14y ago
      This is fair. I would submit that there's a strong argument that, when the total supply of sheep goes up, everyone benefits. I don't think that's true of road throughput; that just benefits the people who are still on the road after you've put up the barrier to entry. I don't see that there's any sort of failure involved in the phenomenon of traffic jams -- I've "happily" sat in stop-and-stop traffic because it's still better than my alternatives. Participate and pay the cost of annoyance due to congestion, or don't and don't. You're on thin ground saying "you need to get off the road, so that it will function better for me".
      - mikeash 14y ago
        When everybody tries to crowd onto the highway, everybody slows down. Beyond a certain point, throttling usage actually makes everybody get to their destination faster. Imagine a roadway with some kind of nasty merge which gets severely jammed up if there are too many cars. If ten cars all try to go through at once, everybody could be stuck for quite a while. If you throttle them so they go through one by one, everyone gets to their destination faster. The same thing can apply to real roads on a larger scale.
mbenjaminsmith 14y ago
"What would there be more of, in total, if you confiscated a bunch of people's cars?" Road. Fewer cars on the road would mean a more constant speed for the cars on the road. "Would you advocate banning most people from a popular public beach on the grounds of overcrowding?" You generally don't have to. Since the benefits of going to the beach are relatively low, people more efficiently self-regulate their usage. That is, if a beach is too crowded to put down a towel, you'll probably leave. That's not the case with taxis. As long as buying taxies and renting them out is profitable, taxi operators will continue to do so. To make things worse, the profitability of driving a taxi is only indirectly related to the profitability of renting that taxi out. The cost of rental is relatively stable while the money made by the driver varies considerably. The drivers absorb short-term (even medium-term) fluctuations in the market.
gcb 14y ago
More people moving. Car is not the goal. There are other means to move people way more efficient.
- thaumasiotes 14y ago
  Be careful. It's very, very hard to demonstrate that other methods of transportation are "more efficient" than cars, even in heavy traffic.