Who maintains the distributed ledger once miners stop making money? (2050?)

[Exeter]

Miners only provide their compute resources to the distributed ledger if someone is making a bit of money from mining. As the return to miners falls by 50% every 4 years, and eventually almost all 21 million bitcoins will be in circulation (with almost none to be "discovered"), who is going to be a miner and maintain the distributed ledger in the year 2050, or 2100, or 2200?

I understand that as miner profit is driven down, miners can take resources off-line, and mining difficulty can scale way back, such that the ledger can be maintained using a lot less resources... but as the ledger grows (52GB growing ~6% per month), lots of resources will still be needed. It doesn't seem like anyone is going to want to provide resources in 50 years...

[Lauda]

The miners will continue earning money from fees. They currently earn a 'little extra' from these fees each block.

It doesn't seem like anyone is going to want to provide resources in 50 years...

You can't know this. There will always be someone who will want to provide resources.

I understand that as miner profit is driven down, miners can take resources off-line, and mining difficulty can scale way back

Mining is unprofitable -> some miners leave -> difficulty drops -> mining is profitable -> more miners join -> difficulty goes up -> mining is not unprofitable. That's kind of a summarized version of what happens. We've seen the hashrate drop in the past.

[squatz1]

I understand that as miner profit is driven down, miners can take resources off-line, and mining difficulty can scale way back

Mining is unprofitable -> some miners leave -> difficulty drops -> mining is profitable -> more miners join -> difficulty goes up -> mining is not unprofitable. That's kind of a summarized version of what happens. We've seen the hashrate drop in the past.

So more or less it's just going to be a lot of miners during one point of time and then less at another, etc. Endless Cycle I would guess?

Fixed broken quote - Mitchełł

[Lauda]

So more or less it's just going to be a lot of miners during one point of time and then less at another, etc. Endless Cycle I would guess?

We are technically fine now and the network is probably much "stronger" (where strength = hash-rate) than anyone anticipated (1 Exahash). There are various ways in which this cycle could work, but we need not worry about it in the short term future. In the long term future, as long as there are adequate fees there should be this "endless cycle".

[romero121]

When miners stop making money through mining, surely there earning will be reduced. This will be compensated by the increased transaction charges as well as there are possibilities to change the production value when the market goes high, which will possibly change technology to continue mining.

[NorrisK]

The potential danger in the difficulty dropping though is the increased risk of attacks on the network.

Imagine that a few big miner farms need to shut down only to than team up to try and create a new chain for double spending or just mining all blocks if people jump to their chain. This can potentially be a problem, however, transactions fees, cheaper mining / hash or a totally different system by that time may solve these types of problems.