Why Bitcoin can't be a currency

Update 3: I've decided to start trying to keep a blog again. I no longer use Tumblr, and I don't intend to try to reconstruct the entire old blog, but as this post is the very first "Bitcoin obituary" listed on 99bitcoins.com, I figured I'd put it back up for posterity's sake (and so that nobody thinks I took it down out of embarrassment). Read the other updates; even with the latest crash I remain convinced that cryptocurrencies have a future, so I'm also not putting this back up as an "I told you so." I still think I was originally wrong.

Update 2: Since trolls can’t seem to resist posting comments on here to make themselves feel smart, if you bother to read anything on this blog besides this post you’d see that my second post on Bitcoin, which is clearly supportive of it, was made before the second “obitiuary” on 99bitcoins.com and probably long before you’d even heard of Bitcoin. If you’d heard of Bitcoin when I made the original post and weren’t a skeptic, you’re either way smarter than I am or not that smart at all.

Update: Since I posted this, I’ve been convinced that due to its unique properties as a purely digital, scarce, easily transferred artifact, Bitcoin’s exchange value is probably enough by itself to prevent a deflationary spiral to zero. See this answer I posted on Quora.

I wasn’t going to make a post bashing Bitcoin, because their FAQ clearly states that its value only stems from the fact that merchants are willing to accept it. Unfortunately, this hasn’t stopped people from pushing it as the currency of the future, so regretfully, I feel compelled to post why this is not so.

While Bitcoin has managed to bootstrap itself on a limited scale, it lacks any mechanism for dealing with fluctuations in demand. Increasing demand for Bitcoin will cause prices in terms of Bitcoin to drop (deflation), while decreasing demand will cause them to rise (inflation). What happens in each of these cases?

Let’s start with deflation, because right now demand for Bitcoin is on the rise. What do people do when they think something’s value will be higher tomorrow than it is today? Well, they acquire and hold on to it! Who wants to give up money that’s constantly rising in value? In other words, rising demand causes demand to rise further. Irrational exuberance at its finest. Deflation begets deflation, ad infinitum, or at least until something breaks. You could make lots of money on Bitcoin, provided you get out of the market at the right time.

Eventually, of course, prices won’t be able to fall any further. Either people won’t be spending their Bitcoin anyway because they’re making so much money just by holding it, or the merchants will get tired of changing their prices every few seconds, assuming they don’t hit technical issues first, like the indivisibility of coins or their software not being able to handle all the zeros after decimal points.

At this point or shortly before, people will start taking their profits. They’ll start spending or selling their hoarded coins. If this manages to start any inflationary momentum at all, you’ll see the deflation scenario played out in reverse. And who’s going to stop it? The supply of Bitcoin is fixed and there is no other use for it besides as a currency. I doubt prices will have much of a chance to rise, since this will happen so fast. Merchants will go from taking one coin for a year of porn to not taking Bitcoin at all, and a bunch of people will be left with worthless Bitcoin.

The reason this can’t happen with government currencies is that government currencies are backed. They’re backed by bullets. If demand for USD starts to fall faster than the USG would like, the USG can just raise taxes without increasing spending, increasing demand and reducing supply simultaneously. There’s a bunch of stuff the FED can do, of course, and the FED tends to act first, but its operations are harder to explain. This is obviously not a perfect mechanism, since bubbles are still blown and popped, but even this mechanism is not available with Bitcoin.

Negative feedback loops like this are basically homeostasis. In nature, positive feedback loops like exist with Bitcoin are lethal; the only thing that’s even kept Bitcoin alive this long is its novelty. Either it will remain a novelty forever or it will transition from novelty status to dead faster than you can blink.