Ripple SOUNDS nice but there are some MAJOR problems

[misterbigg]

I don't think that you know that either since, as you pointed out, not all details are explained.

Not all details are explained but it is written that there is only 100 billion XRP ever, and that 200 XRP is required to be held in an account at all times.

References:

https://ripple.com/wiki/Reserves
https://ripple.com/wiki/Ripple_credits

XRP aren't an asset as Bitcoin, their main function is to avoid spam on the network.

This contradicts the wiki, which states:

"When the Ripple network was created, 100 billion XRP was created. The founders gave 80 billion XRP to the OpenCoin Inc. OpenCoin Inc. will develop the Ripple software, promote the Ripple payment system, give away XRP, and sell XRP."

Clearly, XRP can be sold. If you sign up for the beta and explore their interface, XRP appears just like any other currency unit.

I won't be surprised if there will be the possibility to have more than 100 billion XRP in the future if they are needed.

If XRP can be created by the founders, then it dilutes the value of existing XRP units. We know that XRP have value because it says right in the wiki that they can be traded for other currencies. They are just another currency unit according to the interface.

[HostFat]

We know that XRP have value because it says right in the wiki that they can be traded for other currencies. They are just another currency unit according to the interface.

I'm speculating that there is an open possibility that their number will increase if needed to make the network working better. (miners?)
XRP can be a good exchange system, because they will have a value for sure, but they won't be a good asset, they won't be good to safe money/value for a "long" time. (just speculation...)

[JoelKatz]

Looking over the documentation (https://ripple.com/wiki/) there is a lot of information about the protocol that is not explained. There is certainly nowhere nearly enough information to produce a competing implementation. A lot of important details are swept under the rug. For example, in "How it works", it is claimed that "Ledgers are really hash trees". No further explanation is given.

https://ripple.com/wiki/Ledger
https://ripple.com/wiki/Hash_Tree

This nonsense is repeated all over the documentation, with promises that "mathematical proofs are coming soon."

Feel free to ask for details. I'm happy to improve the wiki. From the wiki:

Here's the high-level view on why our algorithm is stable:

1) Every honest node wants a consensus. They will wait as long as it takes in order to get one. We have no fixed amount of time in which a consensus must be reached.

2) There is no moving target during a consensus window. With respect to establishing that consensus, the world is frozen. There is a fixed amount of information to be known about the state, and more information is always gathered by nodes. They don't forget anything. The ratcheting up of the agreement level required ensures a consensus will eventually be reached.

3) Dishonest nodes cannot stop transactions from propagating to the vast majority of honest nodes. A node would have to have every single one of its connections to a dishonest node. (And we imagine 'core' nodes agreeing to directly connect to each other as a safety.)

4) So long as a transaction can be applied to the ledger and the vast majority of nodes see it before the consensus window, there's nothing dishonest nodes can do to stop honest nodes from including it. (Nodes will extend the consensus window if they aren't getting votes or acquiring transaction sets from trusted nodes that have voted.)

5) If a transaction does not get into a consensus set, but is valid, every honest node that has seen that transaction will vote to include it in the next consensus set.

6) No honest node particularly cares what's in the consensus set, provided it includes transactions that were seen well before the consensus window started. There is no way a dishonest party could get something into the transaction set that shouldn't be there and have that cause any harm. Invalid transactions will have no effect, even if they get in the consensus set.

It is said that the ledger achieves consensus between decentralized nodes without proof of work (a bold claim) and yet, no step by step algorithm is provided. The closest it comes to anything resembling detail is that a transaction is either "passed", "soft failed", or "hard failed." With no other information provided. Answers to important questions, like how Ripple peers are discovered, the messages passed between nodes, who manages the central list of "unique nodes" (for every client's UNL) are totally missing.

This is spread throughout the wiki. You're right that's not concentrated in any one place.
https://ripple.com/wiki/Continuous_Ledger_Close
https://ripple.com/wiki/Ledger_Cycle

Looking over the Ripple forum and reading some parts of the wiki, it seems that Ripple credits ("XRPs") are distributed by hand by the administrators of the system? In what way is this decentralized?

Once they're distributed, those who hold them can do whatever they want with them, and nobody can create new ones. Large numbers of them will be given away soon.

In the other Ripple thread, people are fawning over this rubbish like it's the second coming of Jesus. I suspect these are non technical individuals who have fallen in love with the idea (which is decent) but don't have any inkling of whether or not it can work at the technical level.

There were several sets of technical discussions about this. Some of them are here: https://ripple.com/wiki/Unedited_Notes

I'm happy to answer your questions and improve the wiki.

[JoelKatz]

Not all details are explained but it is written that there is only 100 billion XRP ever, and that 200 XRP is required to be held in an account at all times.

The first part is correct. There are 100 billion XRP in the genesis ledger and XRP cannot be created. It's not quite correct that 200 XRP must be held in an account at all times. Rather than having fees for creating accounts or maintaining ledger entries, Ripple uses a reserve. A reserve is XRP that you cannot transfer but that can be used to pay transaction fees. This also makes it harder to jam yourself into a situation where don't have enough XRPs to perform a transaction. The reserve is enough to cover 2,000 transactions at current rates.

XRP aren't an asset as Bitcoin, their main function is to avoid spam on the network.

This contradicts the wiki, which states:

"When the Ripple network was created, 100 billion XRP was created. The founders gave 80 billion XRP to the OpenCoin Inc. OpenCoin Inc. will develop the Ripple software, promote the Ripple payment system, give away XRP, and sell XRP."

Clearly, XRP can be sold. If you sign up for the beta and explore their interface, XRP appears just like any other currency unit.

They can be bought and sold, but their primary purpose is to pay transaction fees to protect the network from denial of service attacks and spam transactions.

I won't be surprised if there will be the possibility to have more than 100 billion XRP in the future if they are needed.

If XRP can be created by the founders, then it dilutes the value of existing XRP units. We know that XRP have value because it says right in the wiki that they can be traded for other currencies. They are just another currency unit according to the interface.

In theory, a critical mass of users of any system can change the rules. However, there is no mechanism to create XRP other than a fundamental change in the system. While this could be done in principle, just as Bitcoin could be modified to keep the block reward at 25 forever, this would severely undermine confidence in the system and it's hard to imagine everyone needed to make such a change being willing to do so because of the damage it would do.

[casascius]

This is so dumb.  Someone please show me the light.

I see NO POINT in Ripple being decentralized like Bitcoin.

Ripple is a way to transfer debt.  But debt only has value when there is a legal framework to collect it.  That is, a centralized legal framework that can and will refuse to help you collect on debt that hasn't been legally transferred to you.  Until somebody passes a law to the contrary, using Ripple is not recognized by ANY legal system as a valid way to transfer debt.

The biggest Achilles heel to Ripple is not that someone will shut it down if it's not decentralized.  It's that if someone pays you with Ripple debt, and you try to collect on it, and the person refuses to pay, YOU ARE SCREWED.  The debt is worthless.  At best, you can pass this worthless debt on to another bagholder before the music stops.  It's no revolution, it's a way for people to pay people with bits that are worth nothing.  May as well just use SolidCoin.

When someone defaults on repaying lunch money, you suck it up and move on.  But when it's $100k, it's totally a different story.  You won't use Ripple because you might not get paid.  So it is good for nothing more than lunch money.

The world isn't demanding a new decentralized database for tracking lunch debt, certainly not one where you have to go find and pay for some XRP on the market before you can even use it just so your activity doesn't look like spam.  You may as well just use PayPal's iPhone app and click "Request Money".

[JoelKatz]

The biggest Achilles heel to Ripple is not that someone will shut it down if it's not decentralized.  It's that if someone pays you with Ripple debt, and you try to collect on it, and the person refuses to pay, YOU ARE SCREWED.  The debt is worthless.  At best, you can pass this worthless debt on to another bagholder before the music stops.  It's no revolution, it's a way for people to pay people with bits that are worth nothing.  May as well just use SolidCoin.

I think you misunderstand how people pay you. They pay you by making entities that *you* choose owe you money. It's just like the regular financial system -- when you pay me $50, you do it by making *my* bank owe me $50 more. The only entity I ever have to collect from is the one I've chosen to trust.

The world isn't demanding a new decentralized database for tracking lunch debt, certainly not one where you have to go find and pay for some XRP on the market before you can even use it just so your activity doesn't look like spam.  You may as well just use PayPal's iPhone app and click "Request Money".

The idea is more or less to be a nearly-free, decentralized system like PayPal, except with no chargebacks, no entity that can force arbitrary policies on you, easy cross currency transactions, and so on.

[vampire]

I think you misunderstand how people pay you. They pay you by making entities that *you* choose owe you money. It's just like the regular financial system -- when you pay me $50, you do it by making *my* bank owe me $50 more. The only entity I ever have to collect from is the one I've chosen to trust.

And if I don't trust anyone that would make this system irrelevant? Also what does prevent the entity I chose to trust to go out of business?

Scammer's paradise:

Build a reputation like pirateat40 (he had over 100+ positives on OTC)
Issue a million IOUs
Run

[vampire]

So each Ripple's IOU would need to be rated..

So I would rate for an example:

casascius's IOUs at 100%, each $1 owned by him I would give $1

But for pirateat40's IOU at 0.01% (just an example) I would give only 1 cent.

Basically in a nutshell each IOU would have its own exchange rate....

Yea, it looks like a trading platform for debt, not a payment system.

edit: Of course that gets a lot more complicated since each IOU could be dominated in a different currency.

So how any casascius's dollar dominated IOUs would you give for theymos's bitcoin dominated IOUs.

Hmm..

[JoelKatz]

And if I don't trust anyone that would make this system irrelevant?

Pretty much. If you literally don't trust anyone to owe you anything, then you can't transact in fiat currencies using Ripple.

Also what does prevent the entity I chose to trust to go out of business?

It depends just how risk averse you are. You could stick to just regulated financial entities insured by major governments. You could stick to only individuals personally known to you with whom you have "withdraw on demand" agreements. Any one of them wouldn't be able to do you much harm.

Scammer's paradise:

Build a reputation like pirateat40 (he had over 100+ positives on OTC)
Issue a million IOUs
Run

This really wouldn't work. You wouldn't extend significant trust to anyone unless their trust network was worth more than their total trust. So anyone who did this would do it at their own detriment and to your benefit. For example, say you've used Amazon for a few years. When you pay Amazon for an order, do you worry that they'll run off with your money and not ship your order? Even forgetting the possibility of a chargeback, you know that Amazon's business is worth much more than the total value of all the money they're holding at any one time. Plus, even the cost of them betraying you on one typical order will still leave you with a net plus for having trusting them because of the accrued benefit of hundreds of fulfilled orders.

The biggest threat would be a gateway going out of business due to a theft or an insider running off with all the customer's money. If you're very risk averse, don't use the system as a store of value for fiat currencies.

We've tried to design the system so that gateways have very strong incentives to run a solid, reliable business.

Yea, it looks like a trading platform for debt, not a payment system.

There's really no difference. Checks are used as payment and all they do is trade debt.

[vampire]

This really wouldn't work. You wouldn't extend significant trust to anyone unless their trust network was worth more than their total trust. So anyone who did this would do it at their own detriment and to your benefit. For example, say you've used Amazon for a few years. When you pay Amazon for an order, do you worry that they'll run off with your money and not ship your order? Even forgetting the possibility of a chargeback, you know that Amazon's business is worth much more than the total value of all the money they're holding at any one time. Plus, even the cost of them betraying you on one typical order will still leave you with a net plus for having trusting them because of the accrued benefit of hundreds of fulfilled orders.

Let me give you a different example... PayPal.

You have used PayPal for few years.
Do you worry that PayPal will run off with your money or lock them forever?

Yea. Exactly.

Also I have 2 BTC locked up in MtGox.. So much for their IOU. Let's see how AML will affect these IOUs.

[JoelKatz]

Let me give you a different example... PayPal.

You have used PayPal for few years.
Do you worry that PayPal will run off with your money or lock them forever?

Yea. Exactly.

Right, but that's because PayPal can default on just you. Do you worry that they'll choose to shutdown their business while your money is there? Probably not, especially considering there's an entire economy that only exists because of them. But if you did worry, the solution would be to keep as little money with them as possible, not to miss out on the economic opportunities PayPal has created.

A ripple gateway can't stop you from trading IOUs that you hold to others who wish to accept them.

Also I have 2 BTC locked up in MtGox.. So much for their IOU. Let's see how AML will affect these IOUs.

This is the nice thing about the way Ripple IOUs work -- unless the gateway stops paying everyone, their IOUs should hold value. And if the gateway stops, or slows, redeeming, it will become quickly obvious as the exchange rate on their IOUs changes.

[vampire]

Let me give you a different example... PayPal.

You have used PayPal for few years.
Do you worry that PayPal will run off with your money or lock them forever?

Yea. Exactly.

Right, but that's because PayPal can default on just you. Do you worry that they'll choose to shutdown their business while your money is there? Probably not, especially considering there's an entire economy that only exists because of them. But if you did worry, the solution would be to keep as little money with them as possible, not to miss out on the economic opportunities PayPal has created.

A ripple gateway can't stop you from trading IOUs that you hold to others who wish to accept them.

Also I have 2 BTC locked up in MtGox.. So much for their IOU. Let's see how AML will affect these IOUs.

This is the nice thing about the way Ripple IOUs work -- unless the gateway stops paying everyone, their IOUs should hold value. And if the gateway stops, or slows, redeeming, it will become quickly obvious as the exchange rate on their IOUs changes.

Of course unless they issue unique IOUs to you. Since anyone can issue IOUs then a company could have many different types of IOUs.

Which is leads me to the next question.. How do I know which IOU is owned by who? Let's say I trust theymos, but how do I know that the IOU that is given to me is actually his IOU?

[JoelKatz]

Which is leads me to the next question.. How do I know which IOU is owned by who? Let's say I trust theymos, but how do I know that the IOU that is given to me is actually his IOU?

If you only trust theymos, then he is the only person who can owe you money. You cannot hold any other kind of IOUs. Nobody can give you an IOU that you haven't chosen to accept. Internally, the ledger holds a "ripple balance node" for a pair of accounts and a currency. So if you trust theymos to owe you up to 50 USD, there will be a "vampire/theymos/USD" node in the ledger with a credit limit in the "theymos owes vampire" direction of $50. If that's the only trust you have extended, the only way I can pay you $10 is to make theymos owe you $10 or to you make you owe $10 less to someone you already owe money to.

People generally form a ripple payment transaction by knowing who they want to pay and how much. "I want to pay vampire 10 US dollars". To do that, I have to make someone you've chosen to trust owe you $10 more than they do now. I can do that by exchanging any IOUs that I hold or any credit that's available to me. But you decide which IOUs I have to get to you. I can, of course, always pay you with your own IOUs if I can find them. So if I can make you owe $10 less to anyone you currently owe money to, that's a $10 payment to you too.

Of course unless they issue unique IOUs to you. Since anyone can issue IOUs then a company could have many different types of IOUs.

They couldn't issue unique IOUs to you unless you had agreed to accept them. You can't give anyone an IOU they haven't agreed to accept (other than their own).

[misterbigg]

I'm happy to answer your questions and improve the wiki.

Thanks for making an appearance and offering to address some areas where information is scant. I will try to consolidate my list of question marks but for now I wanted to step in and say thanks.

I see that there is a second line of criticism here that claims that the concept behind Ripple is unsound. Let me distance myself from that - Ripple the concept sounds great (more on this below). But Ripple the implementation / specification seems lacking. The impact of a finite amount of XRPs seems hard to determine. Does this mean that eventually it will be impossible to produce new transactions? Again why are 80 billion XRP kept on reserve? Perhaps I just need to re-read the wiki a few more times to have a clear picture but it is not obvious how to analyze the system for correctness given only the published docs.

Whats to stop someone from creating a bunch of accounts and using them to spam the network by creating new bogus currencies?  Is this what the XRP are for? What prevents someone from making a new currency that has the same name as someone else's currency? Who controls the master list of Nodes? How does a node add itself to the list? How do you prevent someone from spamming the list of Nodes? Where is the "order book" (global list of bids and asks for all currencies)? How does someone place orders in the book? What happens when an order is filled? What prevents someone from spamming the order book? Is it guaranteed that everyone has a global view of the order book? How does this scale? etc... These are the kinds of questions that the wiki doesn't answer. There's no way to do an attack analysis because fundamental algorithms are not described.

It seems that the authors of the Ripple software have developed a fully decentralized distributed database that has read, update, and write capabilities (is this true?) Furthermore they have designed it to be resistant to spam, in a way that doesn't require proof of work. This is what's known in computer science as a hard problem. Just solving this problem in a straightforward and robust fashion would be a significant advance (look at the complexity of Freenet, which still has issues). I find it hard to believe that this difficult problem was solved in such a short period of time.

As a concept, I think Ripple sounds great. The trust is definitely an issue but that is not something that Ripple claims to solve (nor should it). In my opinion the biggest value is that there can be an network of independent local nexuses that handle the conversion to and from fiat. Instead of wiring some ridiculous amount of money to an overseas bank (hello MtGox) an individual or business can deal face to face with a local entity. This has the power to address Bitcoin's biggest weakness (the exchanges).

My beef is not with the concept, but with the lack of details about the implementation. And it is exceptionally frustrating that a lot of people are jumping on this bandwagon and singing its praises when we don't have any sort of analysis to determine if the required algorithms are workable or scalable.

[casascius]

I think you misunderstand how people pay you. They pay you by making entities that *you* choose owe you money.

With all due respect, I think you misunderstand what it means to "make" someone owe someone money.  You can't just make someone owe you money, only they themselves can make themselves owe you money by agreeing to pay you.  There is a legal concept of assignment of debt, but a legal system also decides how that is to be done.  Absent a law saying that the Ripple system is how it's done, nothing in the Ripple system has the legal authority to effectuate an assignment of debt, or to make anybody owe anybody anything.

It's just like the regular financial system -- when you pay me $50, you do it by making *my* bank owe me $50 more. The only entity I ever have to collect from is the one I've chosen to trust.

It's totally unlike the regular financial system.  When I pay you $50 to your checking account, I do so by adding the balance to a demand deposit account, which by law they must pay you the balance on demand.  The legal framework that compels them to pay you is already in place.  If the bank one day doesn't "feel" like giving you your money, a court will ultimately tell them they are wrong.

The idea is more or less to be a nearly-free, decentralized system like PayPal, except with no chargebacks, no entity that can force arbitrary policies on you, easy cross currency transactions, and so on.

The problem is that it's like a decentralized screen-door submarine.  Just because it is decentralized doesn't mean it will work.  A debt whose repayment is voluntary and totally optional isn't a novelty, and isn't even a debt.  It's nothing.  Without an entity that can enforce arbitrary policies on you (like requiring you to settle the debts you agree to), the purported debts one can create with Ripple are totally worthless.

[misterbigg]

Without an entity that can enforce arbitrary policies on you (like requiring you to settle the debts you agree to), the purported debts one can create with Ripple are totally worthless.

Hmm...I'm not entirely sure this is true. Consider the case where someone provably posts a fidelity bond (using the Bitcoin destruction method, or the secure way of giving away fees to miners). They could then self-issue credit whose total value is less than the value of the bond.

[casascius]

Without an entity that can enforce arbitrary policies on you (like requiring you to settle the debts you agree to), the purported debts one can create with Ripple are totally worthless.

Hmm...I'm not entirely sure this is true. Consider the case where someone provably posts a fidelity bond (using the Bitcoin destruction method, or the secure way of giving away fees to miners). They could then self-issue credit whose total value is less than the value of the bond.

Then you have the equivalent of Bitcoins.  In that case, just pay someone with Bitcoins, and never mind the whole thing about debt.

This would be like the fiat-world equivalent of a "secured credit card", where you are really borrowing (and paying interest) on your own money.  It's for people who have ruined their own credit to try to rebuild their credit... nobody in their right mind would ever use a service like this for any other reason as they'd simply be paying interest to a bank to use money that is already their own.  One may as well use cash or a debit card, and throw out the pretense that they're using "credit" or "debt".

[misterbigg]

Then you have the equivalent of Bitcoins.  In that case, just pay someone with Bitcoins, and never mind the whole thing about debt.

This is definitely not the equivalent of Bitcoins because after the debt is extinguished you still have the fidelity bond which can be re-used. This allows the the sum of the values of all transactions using the self-issued credit to greatly exceed the value of the bond, as long as at any given time the amount of self issued credit is below the fidelity bond (or else the issuer has an incentive to cheat).

Someone please show me the light....someone pays you with Ripple debt, and you try to collect on it, and the person refuses to pay, YOU ARE SCREWED.

From what I read, it seems like the "Nexus" is the key. You have to trust your local Nexus. You go over to them and exchange your Bitcoins for their self issued credit, which then travels around the system in a series of swaps. Eventually, someone else in your neighborhood receives some of those local Nexus credits and they want to cash out, so the Nexus hands out the previously collected Bitcoins.

In theory this is a great way to handle the decentralization of conversion to and from fiat. You go over to your Nexus and exchange cash for self issued credit (or Bitcoins, if they have them). Later on someone else who is local wants to get fiat so they head to the Nexus and exchange credits and/or Bitcoins for fiat.

This would be like the fiat-world equivalent of a "secured credit card", where you are really borrowing (and paying interest) on your own money.  It's for people who have ruined their own credit to try to rebuild their credit... nobody in their right mind would ever use a service like this for any other reason as they'd simply be paying interest to a bank to use money that is already their own.  One may as well use cash or a debit card, and throw out the pretense that they're using "credit" or "debt".

Nope, the fidelity bond is not the same. For example a Nexus could post a fidelity bond, this would allow customers to feel confident transacting up to below the value of the bond in total value. Over time the Nexus could securely handle many times the value of the fidelity bond, as long as at no given time it extends total credit whose value exceeds the bond.

[casascius]

Then you have the equivalent of Bitcoins.  In that case, just pay someone with Bitcoins, and never mind the whole thing about debt.

This is definitely not the equivalent of Bitcoins because after the debt is extinguished you still have the fidelity bond which can be re-used. This allows the the sum of the values of all transactions using the self-issued credit to greatly exceed the value of the bond, as long as at any given time the amount of self issued credit is below the fidelity bond (or else the issuer has an incentive to cheat).

If one can issue promises far in excess of the "bond", then they are still junk and uncollectible.  So instead of having a promise that is totally uncollectible, you have a promise that is either a) collectible only in proportion to how leveraged the bond is, or b) collectible only if you happen to be lucky enough to collect on the bond before someone else does.  Sounds a lot more like the Federal Reserve ponzi scheme than sound money.

Someone please show me the light....someone pays you with Ripple debt, and you try to collect on it, and the person refuses to pay, YOU ARE SCREWED.

From what I read, it seems like the "Nexus" is the key. You have to trust your local Nexus. You go over to them and exchange your Bitcoins for their self issued credit, which then travels around the system in a series of swaps. Eventually, someone else in your neighborhood receives some of those local Nexus credits and they want to cash out, so the Nexus hands out the previously collected Bitcoins.

Of course.  You are 100% right.  It could work this way.  But the nexus is centralized.  In this case, why bother with a decentralized database?  The Nexus could just use regular database and regular software and keep track of balances the old fashioned way.  Just like PayPal or perhaps MtGox.  Instead of being revolutionary, using Ripple just makes the solution needlessly complex and use way more electricity than needed for no useful benefit.

[JoelKatz]

Of course.  You are 100% right.  It could work this way.  But the nexus is centralized.  In this case, why bother with a decentralized database?  The Nexus could just use regular database and regular software and keep track of balances the old fashioned way.  Just like PayPal.  Instead of being revolutionary, using Ripple just makes the solution needlessly complex and use way more electricity than needed for no useful benefit.

There are a variety of advantages of the distributed database model:

1) You can easily exchange the balances for balances at different gateways. This means people who use different gateways can still pay each other instantly.

2) You can easily exchange balances for different currencies.

3) The market for exchange balances across gateways gives you a reliable real-time view of how trustworthy gateways are.

4) A gateway can't stop you from exchanging IOUs or enforce policies on anything but deposit and withdraw operations.

5) Costs are kept low because no entity can set the system's fees.

6) The gateway can't really freeze IOUs, destroy IOUs, force chargebacks, or the like. (Strictly speaking, they can. But for practical purposes, it's extremely unlikely that they will because they'll make their own customers innocent victims. It's the same reason Mt Gox had to accept tainted bitcoins from their merchants.)

7) People can easily operate small gateways in areas not served by larger gateways and offer 1-to-1 exchanges of their IOUs for a major gateway's IOUs.

8 ) Longer term, ripple may facilitate community credit.

9) You can change what gateway you use without having to notify everyone who pays you or have a change in how you integrate with the payment system.

I think the complexity argument is a red herring. Every payment system can be looked at from a high level at which it's simple and a low level at which it's complex. Ripple is no different. As for the electricity use, that strikes me as a very strange argument, but assuming it's true, I hope the benefits will significantly outweigh the costs.