Will there be more than 21 million bitcoin?

Next question comes from anonymous: Is there any truth to the argument that bitcoin will have more than 21 million coins? The claim is the security model breaks when there are only transaction fees. What are your thoughts on this? I don't think there will be more than 21 million coins because at that point that's not bitcoin anymore, so if bitcoin were to change to have more than 21 million coins I'm pretty sure that that would create a fork where there would be two bitcoin or rather there'd be one bitcoin: the one that was still limited by 21 million coin and then there'd be the other one, which bitcoiners would call a ****coin and as a result you can't change that limit. Now the idea that the model breaks if there are only transaction fees relies on a lot of assumptions about price, profitability, hash rate, whether it's still using proof of work, etc, etc. And of all of those things I think many of those other parameters would change long before the 21 million cap meaning that if bitcoin's current model of consensus didn't work if you keep the 21 million dollar cap, then what would be dropped would be bitcoin's current model of consensus and bitcoin would change to something else; perhaps a proof-of-stake system, perhaps some other thing. Who knows? But it would be far more likely to change the proof-of-work algorithm and use something else than it would be to change the 21 million cap. I don't think that's changing.

The 21 million cap is not defined in the code

And to all of those who who say things like, "Well, it's just a parameter and software can be changed at any point in time," and you hear this a lot from economists who are arguing about bitcoin's scarcity or lack thereof from their perspective: this is a fundamental misunderstanding of how the 21 million cap is actually implemented. It was one of the first things I found in bitcoin when I started looking at bitcoin back in 2012. I searched the source code in order to find where the 21 million limit was defined and I discovered it isn't. It isn't actually defined in the code. Other than as a guard to prevent bugs, there isn't a mechanism that says "if more than 21 million bitcoin, stop issuing bitcoin."

Progressive reduction in issuance of bitcoin

Instead, what happens is you can think of it as the issuance of bitcoin started at full speed with 50 bitcoin per block in 2009 and then bitcoin puts on the brakes. It starts pressing on the brake pedal to slow that down. Every four years it presses harder on the brake pedal. So, you know, 50, 25, 12 and a half, six and a quarter... This progressive reduction in the issuance of bitcoin is how the limit is reached - by pressing on the break. Now, let's use a similar analogy. Let's say that you're trying to get to 21 miles away and about halfway to your journey along these you know after you've gone about 12, well, 10 and a half miles, you start - you cut your speed in half. So now you're going slower and then you cut your speed in half again after half that distance and you're going slower and slower and slower and so essentially it's almost like a zeno's paradox. The way we reach the limit is by slowing down continuously. So, by the time we get anywhere close to the 21 million bitcoin limit we've been pressing on that break for years. Decades, perhaps. And at that point if you take your foot off the brake not much happens. You know, at the end of this you're issuing okay, maybe 10? 20 satoshis? per block. Take your foot off the break and say "We won't divide it anymore. We won't do any more halvings. We'll just continue with this." Well, you're only going to be adding 10 satoshi's to the total every block forever and that's going to take a long time to get over like even one bitcoin being issued. As you can see, if you've been putting your foot on the brake for 100 years and you take them off at the last minute when the car is crawling, crawling, those last couple of inches, you're not going to blow through that limit with any significant speed. You're going to maybe crawl through it and of course the longer you go, the less likely it is that you're going to take your foot off the brake because it makes less and less points to do so. The only way to really defeat this is you'd have to not only stop havings, you'd actually have to reverse them and start issuing more coins aggressively. And again, that's a change that would cause bitcoin to fork and would cause two bitcoins to exist. One of which would immediately be garbage because it had removed one of the most valuable characteristics. So, no. The 21 million coin limit is absolutely definitional for bitcoin. It's implemented in such a way that we've already really held our foot on the brake for 12 years in such a way that it's going to be very difficult. Already 80% of bitcoin have already been issued and now things have really slowed down and they're going to keep slowing down. So, this is not a decision you can reverse it's baked into it. Thanks for watching. If you'd like to support me, please consider subscribing to my channel and supporting me on patreon.com