hi all,
Thanks for all the comments. I am actually the author of the paper. Since I did my research on bitcointalk forum, I knew most of the info therein is already known by you, tech-savvy bitcoiners. My nevertheless intention in writing the manuscript was to inform the issue to the unfamiliar readers (or noobs in your terminology), raise some questions, help alerting more academicians about working on Bitcoin and related scalability issues, and propose what might be called as a minor contribution perhaps.
In more detail, depending on core developers' approach to trade-off of supporting small or large transactions in the future, whichever in priority, they should not only set a strict transaction fee (rather than a donation) such as [a percentage of the transacted amount] or [a fixed minimal fee + a percentage of the transacted amount], but also do this in a manner such that it fills the gap created by the future slow down of price increase together with the block rewards decrease. That is, to fix the total rewards, I propose the developers that they increase the transaction fees gradually over time, to keep up with a fixed hypothetical sum expressing total block earnings (sum of block rewards + tx fees) per block as follows,
https://i.imgur.com/MCWO0tH.pngnote: The block rewards decrease once in every 4 years at once, as we all know it. Hence we should see cuts in the above graph but assuming it is approximated, we can ignore the cuts for the sake of simplicity.
However, as stated in paper, we all know that it is early for this kind of a modification. So I basically propose this kind of a "transaction fee such as a dynamic (gradually increasing) percentage", not now but in the future, when the time comes. I think it is ok to replace "when the time comes" with "when price of a bitcoin or lets say volatility reaches to the stability level of gold or a well-known fiat currency". Well, that's all about it. Although being arguably straightforward, to the best of my knowledge, I have not seen such a proposal before. As a future research, I believe it is crucial to determine/approximate, what a fixed transaction fee/percentage can/might/should be in a userwise/marketwise pacified/stabilized setting, in order to be able to compare tx savings with competitors such as visa/paypal etc.