Even if I put up 2BTC and get nothing, I still have an incentive to approve it to get my 1BTC back.
The profitability for the malicious seller is a function of the probability a given buyer in the system will choose to punish the seller or recoup some money.
Also, is there a time limit? For example, what if the seller ships and buyer receives but is lazy / not incentived by the deposit..
The challenge here is this is an attempt to create a "Justice Algorithm".
I think a reputation based system is probably the solution here, and it doesn't need to be centralized. You could have anonymous reputation nodes -- which would become valueable in the system over time the more trust you have built. Trust seems to be the responsibility of the seller to manufacture by delivering goods as promised. It would be less useful for 1 off transactions with individuals.
You'd also want to calculate some trust score based on volume and value and the non-trivial challenge of preventing manufacturing trust via buying / selling to your self.
In any distributed trust system you can really only calculate based on volume and value and both of those things are easily manipulated since there is no way to identify individuals.
Also you have the situation with your nodes of then requiring an additional layer of trust on the network to determine which nodes are to be trusted.
You can't even do things like lower the trust ratings of people who trust people who end up being dishonest because you don't know that they were dishonest in their trust of them.
Reputation systems don't work with anonymity. They rarely even work without it.
What might work well would be if the amount put up for escrow were determined in part by the reputation of the entity doing the trade. The entities could still be pseudonymous (it's got an identity, but no one knows who is behind it).
There is nothing there to stop sock puppet reputation gaming though which is going to be the main attack vector of any distributed anonymous/pseudoanonymous reputation network.
The profitability for the malicious seller is a function of the probability a given buyer in the system will choose to punish the seller or recoup some money.
Also, is there a time limit? For example, what if the seller ships and buyer receives but is lazy / not incentived by the deposit..
The challenge here is this is an attempt to create a "Justice Algorithm".
I think a reputation based system is probably the solution here, and it doesn't need to be centralized. You could have anonymous reputation nodes -- which would become valueable in the system over time the more trust you have built. Trust seems to be the responsibility of the seller to manufacture by delivering goods as promised. It would be less useful for 1 off transactions with individuals.
You'd also want to calculate some trust score based on volume and value and the non-trivial challenge of preventing manufacturing trust via buying / selling to your self.