Game Theory 101 (#80): Off-the-Path Beliefs

This lecture explains how off-the-path beliefs complicate the search for perfect Bayesian equilibrium. PBE's definition places no restrictions on those beliefs. We therefore have to consider all possible beliefs to see if they sustain an equilibrium.

[dermiugo]

I was finally starting to understand signaling games and the freaking Beer-Quiche but it seems the lectures end here!!! I will be really looking forward for the next one, hopefully it will be online before finals!

[helpIthinkmylegsaregone]

So is a weak sequential equilibrium an equilibrium that simply doesn't occur realistically?
I haven't found a proper explanation of it, I understand that it makes sense via bayesian updating and is sequentially rational, but the "weak" in the term then originates from the fact that it will not be played with positive probability?

[stevendong]

Is there any follow-up video for the off-the-path? Cheers!

[unihedronp]

If we start off with a strict belief but an off-the-path belief is equally good as our primary path then does the other belief also stand as its own equilibrium? For example if the game instead have multiple branches that are reduced to the same expected payoff would it be that multiple branches forms an equilibrium of a mixed strategy or would it be its own equilibrium off the path?

[swapnilkamble]

Which book do you recommend to read with your vids. (I'm totally a newbie, but I follow your vids since time. Plus I want to learn from scratch, I'm totally unrelated with mathematics, except some school learning of maths.)
Thank you.

[joshmohanty]

Is this the same as the intuitive criterion?

[DaveDott]

This is becoming like a second religion to me.

[tukhanhlancaster]

Hello Dr. Spaniel, I have been watching your Logic 101 videos the last few days and found them very helpful. Could you PLEASE help me with these 2 problems using conditional proofs which I have been trying so hard for the last 3 days. Thank you so much.
1. F -> W 1. ~V -> ~S
2. F -> (O&B) 2. ~V -> (~I v ~P)
3. S <-> ~B // W <-> ~S 3. ~I -> ~S // ~P -> ~S

[PunmasterSTP]

Man, it seems like player 1 always revealing himself as a strategy is rather...path-etic? 😎

[eliasmiranda]

What is this?? I don’t get anything... 😬. Some one educate me 🙏🏼💭🙌🏼