ECB's Wunsch says that the case for lifting the minimum reserve requirement is not very clear or convincing

Minimum reserve requirement debates sit at the technical edge of ECB policy, and remarks of this kind from a governing council member typically matter less for what they decide than for what they signal about the balance of opinion on the council, since changes to reserve ratios have historically required broad support rather than a vocal minority. The transmission channel runs through bank liquidity: raising the ratio would drain excess reserves from the system, pushing up money market rates relative to the deposit facility and tightening conditions for euro area banks without touching the policy rate itself, which is why the hawkish wing of the council has periodically floated it as a complement to balance sheet runoff. Pushback from a member known to sit on the more hawkish side of the spectrum carries more weight than the same comment from a dove, as it suggests the proposal lacks traction even among its natural constituency. In past episodes, ECB discussions of reserve ratios have tended to surface alongside debates over the remuneration of reserves and the cost of the deposit facility tiering architecture, so the follow-ons worth noting are whether other officials engage with the topic and whether it reappears in formal council deliberations or remains informal commentary. As a single member's view on a non-imminent tool, the read-through to front end pricing is limited; the signal concerns the internal distribution of views rather than any near term operational change.