Fixed fees aren't that bad

[jamesray1]

I can imagine a black market of fees emerging. Perhaps miners could take side payments from certain addresses in return for prioritizing those addresses.

Good point, not sure how you’d prevent that completely, it seems like you can’t.

But you need to have variable fees for runtime validation (ie. network bandwidth+validation time), and fixed fees for storage.

There are two fundamentally separate fees here: for storage and runtime validation (ie. network bandwidth+validation time). The latter is inherently variable and making it fixed would be absurd, eventually leading to external fee markets where users directly pay stakers/miners the true market price. The former is currently tied to the variable cost which indeed doesn’t make much sense. So they would have to be explicitly separated - ie. only fixed fees for taking up storage.

@vbuterin

Markets will exist whether you want them or not
If you give an agent the power to choose from a list of transactions which ones to include in the next block, transaction senders naturally have the incentive to bribe that agent to make sure they get in first. The genius of traditional blockchains is that they simply accept this effect as a given, and even deliberately formalize it into the benign market of transaction fees. But even if you don’t “officially” put a transaction fee field into the transaction data format, underhanded ways to pay transaction fees will inevitably appear.