If your main point is how few "rogues" (~10%) it takes to switch to a new majority ledger, I think you may be neglecting the arbitrage opportunities that would create. Arbitrage seems to undo the cascade effect of the small exchange float, with arbitrageurs profiting from that market inefficiency.
The arbitrage works if enough of the existing holders of the new chain
truly believe in the old chain, and are in the new chain only to make money. I don't chastise anyone for thinking this way as there is hardly anyone in the myriads of other alts who believes in their alt more than in BTC, so it's convenient to assume that this is the case universally.
It seems the actual scenario posed is that 10% (or 20%) are convinced to move, and 90% (or 80%) remain convinced to stay. If we introduce the additional premise that the majority (80-90%) actually has major doubts as well, then I agree that something like what you're suggesting could happen (ignoring the spin-off option for now), though it depends on the degree of doubt.
It still all seems to come down to a more mundane conclusion: "If 10-20% are deadset on exiting and the remaining 80-90% are shaky and considering leaving, a mass exodus may well be in the cards." (Though as I've said I think a spin-off is what would actually happen, or just a hard fork-off with forkbitrage on the exchanges.)
If the new chain starts out empty, there is no one to sell.
Certainly, but I don't see a scenario where even 10% of bitcoiners would switch to an
empty chain, as that would imply a chain with no track record. To switch, there must at minimum be a very compelling reason and also a reassuring guarantee that things would be all right. It takes a lot of testing with large amounts of money on the line to know a chain is secure. (One might even argue that those amounts need to be within something like an order of magnitude of the chain being replaced.)
A chain with a track record that was so promising would already have received significant investment from bitcoiners who keep abreast of such things (and in such a crisis scenario this would be most bitcoiners), with that investment corresponding to the chain's perceived chances of taking over
on its fundamentals. So then my original point: The surge for no fundamental reason seems like it should incite these people to sell. "1% chance of takeover, so I want it as 1% of my portfolio...but now it's gone up 8x and is ~8% of my portfolio yet still seems to have a 1% chance of takeover. This is just market irrationality, I benefit by selling a bunch at this price."
I also note that Poloniex just opened leverage, which may mean they will allow shorting soon.
Everyone who exits the old chain, obtains some value in the new chain, and the wealth effect as calculated from the actual net new capital flows, is 4x-10x.
I'm not sure how you're using the term "wealth effect" here. It usually is used to mean "people spend more when their portfolio value rises," but here it sounds like you mean an amplified price effect due to thin markets on exchanges. If that's the meaning, then it seems like it would depend on market depth (relevant if you're generalizing from the CKG example).
Insofar as the 90% are mostly strong hands,* not price chasers, they will react by bringing their portfolios back in line. That means they will do the opposite to what the 10% are doing, but with 9x the force: sell their allocations in the minority ledger, now for a giant premium, and buy more BTC at these cheap prices. I believe this negates the "small float" issues of having only a tiny amount of each coin available on exchange at any one time (not to mention that when prices move drastically a lot of coins [and fiat] come out of hiding).
Now you are talking about the
spinoffI'm actually not talking about spinoffs here. I just used the word "ledger" because that's one of my preferred terms for "coin" or "altcoin." I meant that the 90% will sell their allocations in the altcoin and buy more BTC, for the reasons mentioned above, and that I think this negates the small float effect.
And any overshoot is yet a further opportunity for arbitrage to further entrench the majority ledger investors who have the strongest hands.
After taking 2 days to think whether this is correct, and if not, how I would refute it, I have reached the conclusion that I don't believe you are correct, and have given anecdotal evidence supporting my viewpoint. Yet I don't hold a great confidence that many would only because of them, change their thinking on the subject. It is a deep matter and my extensive (if anything in cryptosphere can be classified as such
) research has pointed me to think the way I do, and being familiar with the concepts and data is almost a prerequisite for understanding it.
For a more generalized counterargument, presuming I understand what you intend by the term
wealth effect, I would say that the scenario you posed relies on an inefficiency in the market, and insofar as we define arbitrage as "rectifying those inefficiencies for profit" we can say the effect should be mitigated/eliminated by arbitrageurs - as long as fairly basic market infrastructure is there.