Author: Zefram Lou (zefram@88mph.app)
Specification
Currently, depositors need to pay back a portion of the MPH reward they received, which is 30% for most pools. This paid back MPH is sent to the governance treasury to fund community initiatives such as liquidity mining.
We propose that the payback proportion should be set to 0%. We also propose that the governance treasury be funded in the same way as the dev fund, which is minting 10% extra MPH when minting depositor rewards.
Argument for
Simplifies UX
The existence of MPH payback makes the user experience unnecessarily complex.
- Having “temporary APY” and “permanent APY” is confusing to new users.
- When withdrawing a deposit, the user needs to first redeem their vested MPH, and then use the MPH to withdraw the deposit.
Easier integration
Protocols that use 88mph to earn fixed-rate interest need to maintain a reserve of MPH to cover the cost of withdrawing the deposits, which makes integration more complicated. Removing the requirement to pay back MPH during withdrawal will make integration easier, which will lead to more TVL.
More available cash for the governance treasury
Using MPH payback to fund the governance treasury means that the treasury only receives funding when a user withdraws their deposit, which means there could be a few months or a year of delay between the deposit’s creation and the treasury receiving funding.
This is not ideal for the growth of the protocol. For instance, if the TVL of 88mph suddenly grows by 10x, the protocol would naturally see a lot more activity, and the number of users would increase as well. However, because the governance treasury won’t receive any benefit from this growth until much later, it is difficult for the protocol to quickly launch initiatives to capitalize on the growth.
Funding the governance treasury at the time of deposit allows 88mph to be more adaptive to growth.
Lowers risk of floating-rate bonds
Requiring users to pay back MPH to withdraw their deposit means that under certain conditions, a depositor may not be incentivized to withdraw their deposit at all. For instance, if they had sold their MPH reward immediately after making the deposit, the cost of the MPH payback might exceed the deposited amount if the price of MPH has gone up.
In some of the older 88mph pools, a floating-rate bond holder only receives interest payment from the deposits whose debt they funded when one of those deposits is withdrawn. The possibility that some depositors may not be incentivized to withdraw makes buying floating-rate bonds riskier.
Argument against
Decreases buy pressure
Removing the MPH payback requirement decreases the buy pressure for MPH and makes it an easier decision to simply dump all of the MPH reward you receive as a depositor.
Unfairly distributes protocol income
Part of the rationale for introducing the MPH payback mechanic in the first place was to ensure that existing 88mph users will have a boosted proportion of MPH compared to past users and speculators. If the payback mechanic is removed, most MPH tokens in circulation will be generated by past deposits rather than current deposits, and thus most of the protocol income will go to past users rather than current users. This is unfair to the current users.
Required actions
- Update
MPHIssuanceModel
contract to mint 10% extra MPH to the governance treasury when minting depositor rewards. Should be bundled with 8IP-2’s smart contract upgrade if both 8IPs pass. - Call
MPHIssuanceModel::setPoolDepositorRewardTakeBackMultiplier()
to set the takeback multiplier of each pool to 0. - Update the website to remove mentions of “temporary” and “permanent” MPH rewards.