  Maximal Extractable Value (MEV) has emerged as a new frontier in the design
of blockchain systems. The marriage between decentralization and finance gives
the power to block producers (a.k.a., miners) not only to select and add
transactions to the blockchain but, crucially, also to order them so as to
extract as much financial gain as possible for themselves. Whilst this price
may be unavoidable for the service provided by block producers, users of the
chain may in the long run prefer to use less predatory systems. In this paper,
we propose to make the MEV extraction rate part of the protocol design space.
Our aim is to leverage this parameter to maintain a healthy balance between
miners (who need to be compensated) and users (who need to feel encouraged to
transact). Inspired by the principles introduced by EIP-1559 for transaction
fees, we design a dynamic mechanism which updates the MEV extraction rate with
the goal of stabilizing it at a target value. We analyse the evolution of this
dynamic mechanism under various market conditions and provide formal guarantees
about its long-term performance. Our results show that even when the system
behavior is provably chaotic, the dynamics guarantee long-term liveness
(survival) and robustness of the system. The main takeaway from our work is
that the proposed system exhibits desirable behavior (near-optimal performance)
even when it operates in out of equilibrium conditions that are often met in
practice. Our work establishes, the first to our knowledge, dynamic framework
for the integral problem of MEV sharing between extractors and users.
