What happens to the difficulty level

[hikedoon]

 I've just been asked a question about difficulty but don't know the answer.
 Could someone tell me please?

  What happens to the difficulty level when the last bitcoin has been mined in 2140ish? Does it stop increasing?

[matt4054]

No, the diff retarget algorithm stays in place.

The economics are unknown but it is supposed to have transitioned to a fee-driven reward model by then...  

[Vod]

  What happens to the difficulty level when the last bitcoin has been mined in 2140ish? Does it stop increasing?

The rewards will still go to the miner who finds a block, so the difficulty has to increase/decrease with the mining power.

The reward will be the transaction fees.

[hikedoon]

 Ok, thanks guys. Question answered.

[DannyHamilton]

What happens to the difficulty level when the last bitcoin has been mined in 2140ish?

The same thing that happens with difficulty today.  Every 2016 blocks the protocol requires that the difficulty be adjusted.  If the previous 2016 blocks occurred in less than 20160 minutes, then they are occurring too fast and difficulty is increased proportionally to the ratio between the actual duration and 20160 minutes. If the previous 2016 blocks occurred in more than 20160 minutes, then they are occurring too slow and difficulty is decreased proportionally to the ratio between the actual duration and 20160 minutes.

Does it stop increasing?

Only if the total global network hash power doesn't change, and the average time between blocks continues to be 10 minutes.

[shanerc563]

  What happens to the difficulty level when the last bitcoin has been mined in 2140ish? Does it stop increasing?

The rewards will still go to the miner who finds a block, so the difficulty has to increase/decrease with the mining power.

The reward will be the transaction fees.

Will these rewards be the same as if you were mining and found a block, or will the reward amount change from one block to another depending on the amount of fees in each block?

[franky1]

I've just been asked a question about difficulty but don't know the answer.
 Could someone tell me please?

  What happens to the difficulty level when the last bitcoin has been mined in 2140ish? Does it stop increasing?

its something you dont have to worry about for 125 years.. (after death).. but if you are concerned about your grandchildrens worries about difficulty.. then here are theories..

right now the block reward is worth <$12,000 ($450x25), next year the reward halves and its sepeculated that the bitcoin price will double to counter, keeping the fiat value at around $12,000

now.. if in 125 years people still only want to pay under 5cents a transaction. then each block needs to store 400,000tx a block (200mb~). to keep to a $12k average reward, just from fee's.
if bitcoin cannot possibly store 400,000 tx a block. SOME miners wont mine as its not profitable for them. and as they drop off, the difficulty will slowly drop until there is a profitable equilibrium of mining cost vs income from solving blocks.

however if there is no blocksize limit.. then the sky is the limit for mining income and as long as there are enough transactions with fee's to cover costs, then miners will continue to fight to win that. and the difficulty would increase.

again this is theory, as its talking about 125 years in the future.. using values only known today.. all we know is that in 125years, technology will not be the same.
its possible that 400,000 tx's would be the equivelent data storage as a grain of dust in the future.
after all just 20 years ago a 3gb storage was a large hard drive, now you can get atleast 500gb on something the size of a postage stamp