Quote from: Pajeu on March 11, 2014, 05:39:52 PM

Quick question from someone new to this universe. If the exchange rate BTC USD falls to say, 1BTC = 10 USD, presumably some people already in the BitCoin ecosystem would give up adding hash power, maybe even pull out of the whole enterprise. In this case of less hashing power at the margin, what would happen to the rate of increase of the difficulty? I think the difficulty number itself would not fall, but I´m not sure.

Hashing power is typically only added (en masse) when profitability is possible, even if it's long-term. As you've already surmised, a falling BTC/USD rate not only reduces the amount of power being brought online, it also increases the amount of gear being taken offline as well.

As more and more equipment is turned off, the next / expected difficulty will decrease as well, but the current difficulty will stay the same until all 2016 blocks are found. For example, if half of the miners powered off today, the difficulty would still be '3815723799' until the last ~230 blocks (and counting) are solved.