From xonar's answers I estimate the value of a bitcoin to be about 8 €. This is the value xonar produces. Assuming that he is among the less productive miners with a small capital we may assume that the real value is a few € lower, maybe 4 € to 6 € or $5.5 to $8.5. The difference between value and price of $15 to $25 can thus be attributed to speculation.

I don't doubt this. It's interesting what to operate at a loss means in the Bitcoin economy. It seems quite difficult to make a loss when there's a strong deflation. Even if you don't operate at all, you certainly make a profit. Of course, there's still the final crash, which will produce a few winners and and an army of losers.

Almost right. The price tends to or fluctuates around the value. Value is not equal to cost. Roughly, value is cost plus surplus value.

Never said such things. I acknowledge that the price is not the value. That's obvious when one takes a look at the charts. But I'm interested in what the value is. The big price fluctuations can be explained with speculation.

By looking at the price nobody will find anything about value. You need to look at the composition of the mining capital.

To assess the value of a bitcoin according to Marxian economics I ask miners to answer a few questions. We all may find out from the answers how the price of a bitcoin relates to its value. I also hope to convince some of those followers of vulgar economy (as Marx called it) that their contradicting theories of value are wrong. It's important that only miners answer. I regard as a miner a person who has at least some graphic cards running 24/7 to mine bitcoins and who has been mining for at least 6 months. My questions:

1. What did your mining hardware which you are currently using cost?
2. How much did you pay last month for electricity only for mining bitcoins?
3. How many bitcoins did you mine last month?
4. After what period of usage did you replace your mining hardware or, if you have not, when do you intend to replace it?
5. How much did you pay as wages last month? (If you work alone: How much of your income from bitcoins did you keep for yourself, how much did you invest in your mining business or save to invest it?)
6. How much did you pay last month for rent? (the rent for the rooms where your mining hardware is located)

Thank you for your participation. Soon we'll see clearly what the real value of a bitcoin is.

Generally, that's true. Paper money is made of many material ingredients, means of production and labour. But for Bitcoin this is a problem. The value produced (production costs) per dollar banknote is about 4 cents, whether the note has an exchange value of $1 or $100. But to produce a Bitcoin always costs a Bitcoin. Do you see the problem? Let's make a thought experiment. We assume the dollar was a currency money like Bitcoin. To print a $1 note would cost $1, to print a $2 note $2 and so on. So the only purpose of printing money would be to pay the printer for printing it. The same holds true for Bitcoin. It is impossible that there ever would be given one Bitcoin to the society because the society would have to pay one Bitcoin to the miners to receive one Bitcoin. As I said, the entire model is pointles. We would create a society of miners and hoarders. If the Bitcoin model succeeded – which is impossible because the inevitable crash will stop its expansion –, every person on the planet would work in the hardware or electricity industry.

In your model the currency is neither inflationary nor deflationary. I know this and I don't know why you mention this because it is not related to the restrictions on money creation. You still don't explain how the economy can grow, how the society can pay for any goods. It can't because it has to spend all its money on its money.

More accurate: The value of money produced equals the value of capital sacrificed, with capital being composed of means of production (hardware), used up materials and labour. How could this be desirable? Such a society puts all its efforts into producing its currency. And all it can buy for it is its currency.

Very good point. Few people see this problem. It is absolutely necessary that money can be created at no cost whenever it is needed. If this is not possible, production can not be extended. Normally, money is created by credit. Bitcoin doesn't have this possibility. Whatever it is, it's not a functional currency.

I wonder how Satoshi came up with his magical number of 19% deflation p.a. Did he study some secret economics to arrive at his absurd "insight"? I guess he just set this value because he thought 19% would be a nice annual increase of his fortune.

alexk, I think the monetary system you are looking for, which has not the flaws of Bitcoin, already exists. What do you think of the Ripple project?

The value of a bitcoin is the value of the means of production (hardware, network connection) that is transferred to the bitcoin + the value of the used electricity + the value of the necessary labour (some people must be paid to manage the servers etc.). With this formula you can calculate the value (in dollars, euros, …) of a coin which is produced today. Speculation makes the price fluctuate around this value.
Not necessarily. If the value of the issued money equals the newly produced value, the value of one unit of money does not change. I don't want to defend our banking system. I only say that Bitcoin can't succeed in achieving a constant value of money (Bitcoin is deflationary) because with Bitcoin nobody can create money when needed.
Can you explain how? You need to create money "out of nothing" to grant a loan. In fact, debt is the source of money. Otherwise a bank could only give the money it has and only give it once. That would be pointless.

It's not my estimate. It is estimated that mining will continue until 2033. All Bitcoin owners (and thus the miners) definitely don't loose because of the annual increase in value of 19%. If the Bitcoin community grows this rate is even much bigger. Mining will continue as long as there are Bitcoins to mine or until the big crash comes.

Well, then Bitcoin is completely useless. How would I buy anything if the money does not measure the value of goods? Measuring value is one of the functions of money.
Gold is neither a currency nor is it deflationary. According to this chart it seems inflationary and volatile. The peak price of 1980 was $2251 in 2010 dollars. Today the gold price is $1533 in 2011 dollars. The price will drop as mining gets improved and new deposits are discovered. There is no way back. Mining technology constantly improves and the amount of mined gold grows.

There are three aspects that the current Bitcoin system and Suggester's solution share and which you wouldn't like to have in a currency:

1. A Bitcoin's current value is determined by the currently socially necessary labour time to produce one bitcoin.
This means that Bitcoin is a digital currency money. In the current model the value changes by 19% p.a. on average. But Suggester's model shares the same flaw. Although Bitcoin would not be deflationary anymore, the value still depends on commodities like hardware and electricity. Money can't be created as needed, but has to be produced with commodities. This implies …

2. Money supply is severely restricted.
Bitcoin is only a Ponzi/pyramid scheme without any use besides speculation. You cannot create money as it is needed. There would be no banks, no credits, no interest rates. This system can never work in a growing capitalist economy. It can't measure the value of the produced goods because there can never be enough Bitcoins.

3. A huge part of the economy serves only the mining of Bitcoins.
Since Bitcoins are produced only with electricity and computing, a great part of capital (means of production and labour) has to be expended on the production of the society's money. This is economically and ecologically insane, to put it politely! Even under Suggester's model an economy could only grow as the Bitcoin mining industry grows. Just imagine nearly every worker working for an electricity/Bitcoin mining company. This industry would invest all its profits in Bitcoin mining and draw capital from all other industries. Soon there would not be any other industry than Bitcoin mining and related industries.

All these fundamental problems exist in both the current model and Suggester's model. That's why I suggest to drop this Bitcoin Ponzi scheme altogether.