Topic: Bitcoin & Tragedy of the Commons - page 2. (Read 21902 times)

Now showing at a theater near you: The Lorax And The Tragedy of the Commons

http://www.unitedliberty.org/articles/9674-the-lorax-and-the-tragedy-of-the-commons



~Bruno~

Rassah with no barriers to entry your right it is unlikely larger operations will be more efficient.

One could develop a custom ASIC that gets 20x better MH/$ and MH/W in bulk with a budget of say $10M.  They could then keep them off the open market creating a barrier to entry (a $10M one). Obviously because of the upfront cost that opportunity is only available to those people who have the scale necessary.  Even better you could develop a chip deploy it privately in bulk and then plan a replacement (possibly incorporating a die shrink).  Sell the "obsolete" version at high markup to public as you deploy the superior one internally.  Doing this provides two advantages.  It improves capital efficiency and it also kills off any potential hardware competitors.  If someone was offer 10 GH/s "obsolete" ASICs for $1000 it doesn't matter if they only cost $400 to build.  It would kill off all the FPGA hardware suppliers reducing the chance someday someone makes a competitive product.

The same thing could apply to improved software.  Most miners are open source thus any improvement gets shared with everyone else.  If I released a miner today which was 10% more efficient the network is made more secure but nobody comes out ahead.  Eventually everyone upgrades (and the improvements are copied to other miners).  If you already have a budget of millions for ASICs one could hire in-house developers to work on things like improving stale rates, improving block broadcast delays, etc. 

Also there is the ability to squeeze some marginal efficiency by using lot latency links to give your blocks a "boost" in any potential fork race.  Lastly the more hashing power you control the more likely your block will be the one extended in a split and re-org.  All those things are more cost effective when ammortizing over say 1TH/s then 1GH/s.

TL/DR version:
Without barriers to entry just being bigger isn't better.  With enough capital you could potentially create some barriers that give you a competitive advantage.

Of course they will sell them to the public. PoW will require a much higher demand of faster and more efficient chips. A "stake" holder only needs a few chips, hardly worth even developing, let alone manufacturing. Stake holders could go back to CPU mining.

I'm not really sure how future technologies can be any different from current technologies in regards to returns to scale. Increasing returns to scale suggests variable costs per unit (hash) decrease as production output (hashes per second) increases, but the hash production is linear to electricity (each extra miner costs the same in additional electricity). The only other variable costs are warehouse storage space (especially if renting), cooling/ventilation, and internet bandwidth. Increasing returns to scale would mean having 20 miners is cheaper to run per miner than having 10 miners, but the additional electricity for each additional miner is constant, as is bandwidth, and though you save a bit of money by warehousing them all close together, you will spend more on keeping that tight cluster cool. As I mentioned earlier, I see mining as more analogous to crop farming than, say, manufacturing or providing electricity, meaning competition is perfect: my hash is just as good as anyone else's, even if my costs were different. Maybe someone can explain where monopoly inducing increasing returns to scale come from?

Good points by cunicula. Overall I've come to the conclusion that this issue could prove quite challenging. The good thing is that there are many years to work on this, currently our mining network (and thus security) is oversized compared to the size of the market. It will take a long time until this starts to be a real problem but it's good that people are thinking about it already.

This is right. The most likely basis for mining oligopoly is several companies competing for monopoly control using proprietary mining technologies. Once one company has significantly better technology, then it will end up as a monopolist.

If the technologies are not proprietary and instead are sold on a competitive market, then there are three possibilities:
1) The technologies have increasing returns to scale. This will lead to monopoly.
2) The technologies have increasing returns to scale when scale is small to medium, but decreasing returns to scale when scale is large. This could support oligopoly.
3) The technologies have constant or decreasing returns to scale. This would lead to competition.

While oligopoly is possible, I think that monopoly and perfect competition are both much, much more likely as long-term equilibira.

I agree with your point, but way too many nines there. There is a tiny cost to including a transaction (verifying ECDSA sig, more bandwidth to broadcast the block) which is larger than a satoshi.

It will be interesting to see if the people currently selling ASIC systems will go on to mass-mass-produce them to the point that anyone can afford a few chips. Maybe instead of letting the public have them in huge numbers they will, as soon as they have their "stake", use their proprietary hardware to make a bid at the monopoly.

-MarkM-

That's a nice tautological statement. Oligopolists can only operate if they act as an oligopoly.

I wanted to reiterate a point about market power and its (lack of) potential to save the day.

It is possible that oligopolistic mining could lead to sustained high fees. However, that oligopoly cannot be sustained unless there is a significant entry cost. As long as mining is possible to do efficiently on a small scale, oligopoly will not be possible. Therefore, there will need to be a fundamental change in the technology before oligopoly becomes possible. (For example companies develop patented hashing technologies that are not available to the general public).

Something Mike Hearn has mentioned before is that in the future people may just pass around unconfirmed tx and only when it's for something fairly important will someone bother to pay for confirming all the tx that their 'important' tx has as inputs.

I guess that scenario assumes pretty high fees.

Has this part been considered?:

Senders pay fees, but the only ones actually benefiting from the fee's purpose (transaction being included in a block) are the receivers. So, wouldn't the receivers, aka merchants, be the ones with the interest in getting their transactions through, and as soon as possible, and thus wouldn't they be the ones to keep track of fees charged by pools, have contracts with pools, and force the senders to pay a fee of their choosing? If they only charge the lowest fee along with their merchandise, they'll have less guarantee of getting their money confirmed quickly (or if the transactions/block reach their limit, at all). So the incentive to enforce fees may even be higher with merchants than with miners.

That is the point people who naively believe a market will flourish fail to understand.

99.9999999999999999999999999999999999999999999999999999999999999999999999999999 99999999999999999999999999999999999999999999999999999999999999999999999% of the work in solving a block is .... solving the block.  0 transactions or 20,000 transactions the amount of work (and thus cost) is roughly the same.

So there is no economic value to exclude any paying transaction of reasonable value and no economic value in including free transactions so it is more like this.

User fees.
For a fee of 1 BTC avg confirmation time is 10.087 minutes.
For a fee of 0.1 BTC avg confirmation time is 10.09 minutes.
For a fee of 0.01 BTC avg confirmation time is 10.1 minutes.
For a fee of 0 avg confirmation time is 20 weeks.

Now this assumes min fee is 0.01 but in actuality it is 1 satoshi.  1 satoshi will guarantee relatively fast confirmations  0 satoshis will guarantee unbelievably slow confirmations and exponentially higher fees will only marginally decrease confirmation time.  Fees will avg 1 satoshi per confirmation until network gets small enough that a monopolist can gain 51% of network, exclude other blocks and raise fee prices creating a cartel.

How to fix it?
No idea.  Putting a more realistic minimum fee is a bandaid but partially solves the problem.  A better fix would be to have difficulty rise based on value of transactions in the block.  This means avg time per block will have more variance but it directly couples the difficulty with number of transactions and thus puts an economic cost on including transactions and makes fee pricing more plausible.

I think we're finally on the same page. First of all I believe that altruism is no different from self-interest, it's just an indirect version of it. For example, humans in stone age communities probably learned to be friendly to each other because it increased their chances of survival. I have never seen a case of altruism that can not be explained by self-interest, if you think it through.

I now agree with you that small individual miners do not have any incentive to ever mine anywhere else than the low fee pools. This seems to be clear. I also think that Bitcoin mining will become more centralized than it is now, FPGA and ASIC chips will slowly but surely kill off all GPU mining except perhaps those that either have fixed electricity costs or those who effectively use the GPU's for heating.

This development will lead to a situation that such a small part of Bitcoin mining is done by small individual miners, that what I'm talking about could work theoretically. It's important to remember that this whole issue is not an issue in many years, there is plenty of time for the Bitcoin mining network to evolve before that.

When we talk about superrationality, it's the bigger miners that are most rational about their profits, just like in regular business. There is no emotion, there is self-interest and it doesn't matter if it's direct or indirect, altruistic or not, as long as the end result is more profitable than the alternative, it's better. So I do think that players with some bargaining power would attempt to get others on board the high fee train by changing and then hoping others react.

With big rational players there is no emotion. They really do not care even if the low fee pool would be immediately more profitable. Their bargaining power allows them more profit than if they did not use it and if someone gets more profit than them by using the low fee pools, so be it.

Of course there is a limit on how large the difference in profitability can become before even bigger players will start wondering if they are being exploited. I think this could actually lead to a not-so-stable equilibrium, meaning that when a few big players defect from the high-fee train, everyone else is forced to defect as well.

I'm honestly not sure if this is a good way to do it from the user's perspective, one day the fees are that and next day they are this. The variance could potentially be fairly large. Maybe this is one of those aspects where my plan fails

On the other hand, I guess my earlier description could work also, that miners (referring to big miners) start to change back to high fee pools fairly quickly when they notice that defecting had negative consequences.

It's not short term vs. long term. It's not hopping between pools to increase profits. It's each miner vs. everyone else. If I'm a selfish miner who only cares about my own long-term profits, my total profits will be higher if I mine at a low-fee pool. Always. I don't hop. I stay in this pool forever. Going to a high-fee pool will not increase my profits, not the profits I have now and not the profits I will have at some future time. And while I'm permanently staying at the low-fee pool, I hope there will be suckers who mine at a high-fee pool and increase my profits. If there are no such suckers I'm screwed, but in this case I'm screwed either way, even if I chose to go to a high-fee pool.

Without a protocol change, the only way to change this equilibrium is with an enforceable way to aggregate hashrate (such as an agent buying mining capacity as described by freemoney).

If we assume that everyone is selfish and that this is common knowledge, this won't happen, unless each pool individually is big enough to change the equilibrium. Of course, if some pools are altruistic (or at least superrational) or believe others are, this is a possibility.

Just think of it from the perspective of a mining pool operator or someone who runs a major mining operation. If they hold some bargaining power it makes sense to them to constantly change the fee threshold to a higher amount, for at least a little while and see if others want to do the same. Other operators see this and decide that well, we'll do it too. Thus the fees start going up and profits start increasing for everyone. Then we see defections and it starts getting worse again. Cycle restarts. In reality this cycle will actually be continuous and never ending, which creates a sort of equilibrium.

As far as I understand it, the more hashing power there is in the high fee pools, the better off everyone is, including you. If a sufficient amount of miners defect from high fee pools, you're worse off than you were originally, regardless of how profitable it seemed at first. This means that if the profits to be gained in the short term are not adequate enough, many miners will not bother to hop at all.

I agree. The balancing factor comes from the fact that miners will be constantly pool hopping in an attempt to increase profits. FreeMoney is correct that mining would probably become a bit more centralized from the effects of people selling hashing power to keep it simple. It's important to understand that the miners are not the only ones who control this. Pool operators can change their fee threshold and they hold fairly significant bargaining power.

Also, as I already said, if everyone knows that all you get from defecting is a short term increase in profits, it isn't that straight-forward to calculate if you even want to do it. I still think that there would be a strong equilibrium where major mining businesses and pool operators constantly try to put the fees as high as they can. Not by some cartel or conspiracy, simply because that way all miners, including them, get more profit.

There will be defections and in the end users have a lot to say as well, if they're not willing to pay huge fees then it becomes very unprofitable to run a high fee pool and the pool is forced to lower their threshold or the miners will switch. In any case miners will always attempt to put the fees as high as possible, anything they can get away with. This will be balanced by the low fee pools and by what users are willing to pay but still, they will not stop trying which is exactly why I think that what I'm talking about does work.

I don't think that's right still. Imagine this game (I know if isn't  close to the mining situation just an example of clear TOC).

There is a $10 pot. Any of 10 players can take the whole pot at any time. Every minute the pot doubles.

It is obvious to everyone that if they can all agree they'll make a fortune. Otherwise nearly nothing. But they can't expect everyone to trust everyone else so they all grab for it.

Mining is pretty different, if even a few can agree they can prop it up. I don't even expect tiny individuals to do that. I expect somone(s) to buy up some significant enough amount of power. Probably there will be plenty of miners who'd rather not be subject to the whims of difficulty and variable fees and will sell for less even that the expected return to reduce variance.

In some cases tragedy of the commons is overcome when there are additional factors at play. It depends on the ratio between incentive to defect and the stabilizing forces.

But I think it's much more prevalent than you think. Voting is a classic example. AFAIK voting rates in US are very low, and it is generally agreed that the total welfare would increase if everyone voted (the total effort of all people voting is justified by the election of a party which better addresses people desires). But for each person, the effect of his own vote on his own welfare is negligible, so most people pass.

Another example is software. Would it not be better if instead of dealing with DRM, registration keys, closed platforms and so on, companies would allow anyone to download the software, specify a price, and receive payments on the honor system? If this was in place and everyone (who pay under the current system) paid, everyone would be better off. But everyone would be incentivized to spare himself this cost, which eventually results in the breakdown of this model and resorting to DRM. (Some people have offered software on an honor system, somewhat successfully, but mostly because of the novelty factor - it doesn't scale.)

There are no doubt cases where it could have occurred, if society hadn't been able to redefine the rules to dispel it.

People have been suggesting all sorts of factors that would mitigate the tragedy of the commons problem in Bitcoin mining, but I still doubt that they will be enough quantitatively. We need something about which we will be able to be much more confident.

Again, if I am a small miner, the effect of my mining on the equilibrium is negligible. By going to a high-fee pool, I'm increasing the frequency of high fees by about 0.0001% (which I will also enjoy). If I go to a low-fee pool with twice the total reward, I increase my rewards by 100%. I would much rather that all other miners go to the high-fee pool; but whether they do or don't, I'm still better off at the low-fee pool.

In other words: My personal benefit from defecting is always higher than my share of the global benefit of me cooperating. I lose from other people defecting, not from me defecting. (Unless I'm a sufficiently large miner.)

You need some balancing factors to prevent that from happening. And they need to be stronger than the total incentive to defect.

Good points by FreeMoney. That is certainly a market where more awareness helps. If everyone understands that certain actions will benefit all (including me) and certain actions will be harmful to all (including me) then I don't see how the tragedy of the commons can surface in any significant way. It doesn't require a cartel either, all serious miners simply know that it makes no sense for them to accept only low fees because it will crush profits very quickly (in a matter of hours, once user clients realize that you can make fast transactions with low fees). So the feedback is very quick as well especially if there is a lot of Bitcoin usage / high number of transactions.

There will of course be defections and that's natural. Someone decides to mine at a low fee pool, hoping he can get away with it. Eventually these people notice that the grass wasn't greener on the other side, they only got more profits for a short while. Too many people defected and now they profit less than they did originally at the high fee pool. These people will change back to high fee pools in an attempt to increase the incentive for users to pay higher fees. Thus we have a constant back and forth which results in an equilibrium.