WASHINGTON, D.C. —
Second, the cap on the supply of bitcoins may reassure people that there will be no inflation, but in fact it ensures that it can never go into widespread use. A currency needs to be elastic — that is, its supply has to rise and fall in order to keep prices stable even as people's demand for money varies. Part of the reason the Federal Reserve was created a century ago is that the dollar was at that time an inelastic currency, its supply was basically fixed based on how much gold banks had in their vaults. That meant that when harvest season came around in what was then a heavily agricultural nation, there was always a shortage of cash and a spike in interest rates, and in some years a banking panic.
Bitcoin exacerbates that problem. Its supply is capped in the long run. That means that if it ever came under widespread use, demand for bitcoins would rise faster than supply (which is what happened between February and earlier this week), and the price would rise rapidly. That may sound good — your money is more valuable! — but in fact it means that prices of goods and services are plummeting. That's deflation, which as the Great Depression showed us is not much fun. It is a situation in which everyone has every incentive to hoard money rather than spend it, leading the gears of commerce to grind to a halt.
In effect, bitcoin is a reminder of this fundamental truth: To function in a modern economy, you're always putting your faith in something, whether you like it or not. And you may not like putting that faith in a powerful, independent central bank imbued with power from the state, but the alternatives may just be a lot worse.