Wednesday, April 10, 2013

Bitcoins explained for normal people -or- please get back to work


Bitcoins have been taking the world by storm, and what I’ve been reading has been making me angry. Consider this post my version of:
http://xkcd.com/386/

In short, I believe bitcoins are an interesting experiment, but that most people currently promoting bitcoins stand to profit from luring more folks into buying them and believing in them. In other words, they have a stake in convincing you to join in.

In this explanation, I hope to educate readers about how bitcoins:
  • cannot do what normal money does and 
  • as an investment are a pyramid scheme and thus
  • are not “the new world order”.
I will first try to explain what bitcoins are and aren’t so you can make an informed decision if you want to partake in this gold rush.

A first stab: naive digital currency

Let’s start with a simple experiment. I want to start a currency, but not go through the hassle of actually minting coins or printing notes. So what I do is I take otherwise unremarkable pieces of paper and write numbers on them, say 0 through 21 million, and I tell everyone all those numbers are money.

And if people believe me, it will work, and you can then do payments with these pieces of paper. Interestingly, we don’t even need the pieces of paper: it is the number that is the money (there is no shortage of paper). This also makes it a breeze to do payments online - no need to ship paper, no bank involved!  Instead of keeping large stacks of paper to prove our worth, we only keep the numbers in a file somewhere (if you delete the file, you lose your money though).

The problem now is that nothing stops people from spending their money twice. So I take my number 3141593 and use it to buy bread and simultaneously order some stuff online with it. Clearly, numbers as money are neat in theory, but soon the currency collapses since everybody has a copy of every number. People can just keep spending their numbers, and no one wants them anymore.


Second iteration: keeping track to prevent double spending

Within bitcoin, all transactions are recorded. So if you spend a bitcoin (which, mathematically,  is a very large number), that transaction gets broadcast and stored in the network. If I then try to spend the same bitcoin again, I’ll find that the network refuses to register that transaction -  because there already is a longer transaction chain recorded that includes the new owner. Thus, double spending is prevented.

This means two things though:

  • Each transaction is logged! So if you get your wages in bitcoins, and spend them at the local supplier of recreational drugs, that transaction is recorded forever. This might haunt you at a later stage. At the very least your employer now knows where you spend your money.
  • Recording & verifying the transaction takes time. Because the bitcoin network is fully distributed and has no trusted central hub, transactions are only assumed to be distributed if enough parts of the network have verified them. This takes around 10 minutes, and for absolute certainty, an hour is recommended. So forget about a quick shopping trip using bitcoins.

Third iteration: adding back privacy

This recording thing does not sit well with anyone and is an obvious flaw. A “solution” has been found however. When someone wants to send you money, you create a fresh identity for that transaction.

By exchanging these custom identities, each individual transaction gets a sheen of anonymity, but not really. Because whole transaction chains are available, it is nice that individual transactions are anonymous, but if you want to spend your coins, you’ll link them together on the outgoing transaction anyhow.

Fourth iteration: money supply issues

So where do the bitcoins come from? In a normal currency, a central bank creates money, usually in line with the (intended) growth of the economy. As bitcoin has no central bank, means have been found to allow people to ‘mine’ for new coins at a predetermined rate.

There is a steady supply of new bitcoins, mathematically set at 150 bitcoins/hour up to 2017, at which point this will slow down to 75 bitcoins/hour. Eventually, there will be around 21 million bitcoins, and not ever more.

This makes it impossible to look at bitcoins as ‘money’. Whole economies have been killed by setting the money creation rate wrong (too low in 1710 in France causing deflation, too high has happened to almost every currency, resulting in inflation). While we can be angry at how central banks did not stop the current ‘old school currency’ mess, bitcoins have only one money creation rate, and it is fully set in stone.

In short, the bitcoin economy may grow, but the number of bitcoins in circulation can not be matched to that growth. As long as the interest in bitcoins grows faster than the creation rate, as is currently the case, the bitcoin shows heavy deflationary behaviour - each individual bitcoin becomes worth ever more ‘regular money’, making it in effect a very bad idea to actually *spend* your coins.

Under deflationary conditions, in nominal terms, things keep getting cheaper. Why buy a car now when you can be sure it will be cheaper next week? Such conditions have killed whole economies.


The issues in short


  1. Bitcoin transactions are (way) slower than regular money transactions (10 minutes - 1 hour)
  2. Every bitcoin transaction leaves a publicly visible trace that can only be obscured but not removed
  3. Because the bitcoin supply rate is fixed, the regular money value of bitcoins will fluctuate wildly, making them unsuitable as normal currency
Many bitcoin adherents will agree with the points above, and offer two answers:

  1. Bitcoin is not a regular currency, but an investment
  2. Most of the problems can be solved by calculating the bitcoin value of a transaction against current conversion rates to regular money

This holds no water. If we look at bitcoins as an investment, this only works if we can convince people to join in and thus grow the bitcoin economy. But why would they join in? Why, because the value of the coin keeps increasing! This is known as a pyramid scheme, where people who join in first take the money of those that enter the game later. These in turn only make money if they entice even more people to take part. In the mid 1990s, pyramid schemes wrecked the Albanian (real) economy, leading to the 1997 Albanian revolution.

If we look at bitcoins as currency, but admit that we still need traditional money as an adjunct, then bitcoin is attempting to do a revolution with aid of the establishment, something that has rarely worked. Any of the purported advantages of bitcoins disappears if it needs regular currency as an adjunct before being useful!


Finally

So, before jumping on the bitcoin bandwagon, realize that as a currency, bitcoins are flawed, and as an investment, you are late to the game, and you are merely funding the folks that got in earlier. And before you know it, you'll find yourself enthusing about bitcoins at birthday parties because, you know, you are now part of the pyramid!

I wrote this page out of sheer frustration that many of my smartest friends are devoting enormous amounts of energy to bitcoin-related projects and not actually contributing to their own or society’s well-being.

Hence the second title of this rant: and now get back to work.

11 comments:

  1. I think that it's great that Bitcoin is getting so much attention. With the run-up in price and various other items of Bitcoin related drama, it is becoming a minor media darling. Good for the Bitcoin crew! They deserve some recognition for all the long hours in relative obscurity.

    But can we all remember for a minute that this is an experiment? That this is the first serious step on the way to a world where dependable digital cash exists? And that digital cash is a really important thing and will make the world a better place? (https://www.eff.org/deeplinks/2011/01/bitcoin-step-toward-censorship-resistant)
    Note: The EFF no longer accepts Bitcoin donations. While they philosophically support the work of the Bitcoin developers (and other digital cash developers) they decided to avoid the possible legal complications of an experimental currency.

    Bitcoin will evolve and may or may not fail. To own bitcoins is to be involved in this story, a good thing to remember. It is exciting to see this play out in the wide world with real unpredictable consequences. It seems likely that the digital cash story will go forward and Bitcoin is involved in that story for now.

    So we'll see how it works out. And hats off to the Bitcoin development crew and good luck to them.
    Share this discussion

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  2. And there I was thinking that Bitcoins was yesterdays news. Nice to hear they are still around. I am curious about how it will develop. Nice experiment if you ask me.

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  3. Interesting Bert. You make it very clear that as a practical, direct currency bitcoin has no future.

    However, as a economic value-sink it might have a use, but then it needs a strong and robust layer around
    it with services and institutions (regulated by local laws). I think that is what we see happening: depositories,
    exchanges and derivatives markets. Once this infrastructure is in place, it could well be a usefull part of an asset portfolio.

    The idea of having no central authority is a stong one, and the network where the transaction logs reside could be pretty robust. DNS architecture springs to mind, and im sure future digital currency schemes will borrow heavily from these ideas.

    Its interesting to watch this space in any case.

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  4. Sigh. I call your post the "that baby will never play football, look how small he is" fallacy. It falsely assumes current conditions will hold forever.

    Bitcoin is new. Its value will not fluctuate wildly forever, eventually the market will settle on something.

    "Bitcoin transactions are (way) slower than regular money transactions (10 minutes - 1 hour)"

    This is wrong.
    https://en.bitcoin.it/wiki/Double-spending#Race_attack

    A merchant can indeed safely accept transactions in ~10 seconds, assuming they configure their bitcoin node correctly. I imagine soon merchants will not even have to do this themselves, they could trust a 3rd party to handle it for them.

    Given that none of the flaws you pointed out are really flaws, it's not late in the game at all.

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  5. Jeff, if you follow your link you'll find that the attack is real and can only be "lessened". This is not what people want for money. I'm unsure where you get the idea that the market will "settle".

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    Replies
    1. By "settle", it is as below. Let's take gold as numeraire (governments tend to print more their currency so not proper for this "settle" discussion) and suppose there are only 100kg of gold on earth, then a good's price in gold as X kg and its price measured in bitcoin as Y, then X * 100 = Y * 21MM.

      By "money supply to pack with economy development", the real reason is physical: we have cent as the least unit. So it is not easy to have a good's price to be 0.1 cent when the economy becomes larger. But bitcoin has no practical least unit (it's least unit is 10^-8) so it is possible a car costing 10 bitcoin will be 0.01 bitcoin some day in the future if the economy becomes 1000 times larger. Only after the economy becomes 10^8 larger then bitcoin will face "money supply to pack with economy development" issue. Before that, the real wealth of the people is the same, however.

      I think the only issue and the most important one is whether the way to prevent double-spending is economical or not. I hardly imagine how to handle the transaction log 100 years later.

      Delete
  6. Thank you for the helpful information. I also think that Forexminute.com is a good website, it has very helpful information for trade bitcoins, bitcoin news, breaking forex news, forex trading, commodities news, etc.

    ReplyDelete
  7. this waas a very good article for bitcoin geeks
    i like the way you explained everything ...
    i got this one more interesting article related to the same topic seems you should have a look over this ...

    the security of the whole thing is on sake due to gov interference
    http://born2hack.hpage.co.in/thiland-bitcoin-ban_80532254.html

    ReplyDelete
  8. I believe in bitcoin and its power to become a potential currency of the future. If you don’t want to get left behind in the bitcoin bandwagon, check this infographic to know more about this cryptocurrency: http://bitcoindaily.com/bitcoin-daily-bitcoin-infographics/

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  9. Yes you were right bitcoin is unsuitable as normal currency as it is a virtual currency. Bitcoins are safe to use unless users publicize their wallet addresses publicly, no one can trace transactions back to them and even if the wallet address was publicized, a new wallet address can be easily generated. This greatly increases privacy when compared to traditional currency systems

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  10. Your blog provided us with valuable information to work with. Each & every tips of your post are awesome. Thanks a lot for sharing. Keep blogging,
    bitcoins exchange rates

    ReplyDelete