
Braess' Paradox and the Price of Anarchy (2019) - luu
http://cadlag.org/posts/braess-paradox-and-the-price-of-anarchy.html
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beefman
This misses the seminal result of Roughgarden & Tardos – the price of anarchy
in the example is 4/3, but that is also the maximum price in any network where
travel time scales linearly with traffic.[1]

[1]
[https://theory.stanford.edu/~tim/papers/routing.pdf](https://theory.stanford.edu/~tim/papers/routing.pdf)

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celias
Up and Atom has a video on Braess' Paradox, among others
[https://www.youtube.com/watch?v=cALezV_Fwi0](https://www.youtube.com/watch?v=cALezV_Fwi0)

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aaron695
Contrary to the video Cheonggyecheon is not Braess Praradox.

For instance "To address the consequent traffic problem, the Cheonggyecheon
Restoration Project Headquarters established traffic flow measures "

"The project contributed to a 15.1% increase in bus ridership and a 3.3%
increase in subway ridership"

It was a billion restoration project.

It is a good example how any superficial improvement to traffic where a road
is removed is called Braess' Paradox.

Or anytime a road is added or upgraded and it gets worse for anyone, everyone
says Braess' Paradox.

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Hermel
Economically, this is a nice illustration of “externalities”. Each
individual’s choice negatively effects the outcome of the others.

I wonder if the efficient outcome is restored again by allowing agents to pay
each other to take a certain route. For example, agent 1 could get 0.009 from
the other 99 agents for agreeing to take the detour. Thereby, the 99 agents
save 0.01-0.009=0.001 each and the one agent gains 99*0.009-0.5=0.4 or so.

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Ar-Curunir
Isn’t this just because you assume that the agents are acting selfishly? Why
not just introduce some local coordination to minimize overall costs?

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edh649
Because in a traffic scenario people do act selfishly!

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sudosysgen
In practice, not really! Only when others around them also act selfishly, or
there is urgency.

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bobthepanda
People may not act outwardly selfishly, but people may not realize that their
individual action is selfish from a game theory perspective.

Everyone takes the highway because it is the fastest way to travel. However
every additional car does slow it down. And this will continue until travel
times on the highway either match non-highway travel times or the road
literally can't handle more people. But no one thinks that driving the car to
the grocery store across town to redeem a coupon is "selfish", because
everyone thinks they're in traffic, not that they _are_ traffic.

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aaron695
Braess Praradox is fake news.

Price of Anarchy it a legitimate issue.

See beefmans link for how they tie together better.

I'd like to know if there's anything interesting outside of a lab to the
result.

