PoS coins use the number of coins held as the basis for their signalling system. Since coins have an exchange rate, they obviously do not fulfill the criteria of having no value, either practical or intellectual. Thus PoS is not an viable mechanism for honest signalling.
Aren't you confusing the stake (which can be reused to provide signaling for many transactions over time) with the coins (which can only be used once)?
The stake is worthless as far as I can tell. Stake is just showing someone what you own, not actually giving it to them. Would someone pay me just because I show them that I have a lot of money in my wallet? I can show what's in there a million times without losing a cent.
No, it's you who is confusing. Let me rephrase the issue here and hero members correct me if I am wrong:
- You need to expend real world resources to produce something (otherwise) worthless (eg. hashes), which are expended when you use it to "vote" on which chain is the longest. You cannot double-spend hashes, so there is always a cost if you want in the game, and the reward (coinbase) tends to the marginal cost.
- In PoS, you can vote with the same coins in all universes of the present, as well as the past and future, and not produce anything, and it does not cost anything. So it is a worthless system to determine which chain is the longest (no cost == nothing at stake). The only reason PoS advocates argue against it is that they have not even understood the basic problem.
I agree with you, but this is a different point than the one Justus was making. He was saying the proof has to have no value anywhere else. To me, at least on this criteria, PoS seems to fit.