Tiered Reserve Remuneration

A tiered reserve remuneration system pays interest on bank reserves at multiple rates, typically offering a higher (often zero or positive) rate on a threshold amount and a lower (often negative) rate on excess reserves beyond that threshold. The goal is to soften the blow of negative interest rate policy on bank profitability while preserving the stimulus effect on overall money conditions.

The profitability squeeze behind tiering

When a central bank charges negative rates on all reserves, banks face a brutal arithmetic: they must either pass the charge to their depositors (risking deposit flight), absorb the cost themselves (crushing net interest margins), or reduce lending to preserve profitability. The first path is often politically explosive; the second erodes banks’ viability; the third defeats the purpose of stimulus.

Tiered remuneration splits the difference. The central bank exempts a portion of each bank’s reserves from the negative rate, paying a neutral or positive rate on that tier instead. Banks can thus preserve some profitability even as they hold abundant reserves. The exempted tier is typically calibrated to give banks breathing room—enough to cover a portion of their retail deposits at near-zero rates—while leaving excess reserves subject to the negative rate. This preserves the incentive to lend out the marginal reserve.

The mechanism thus keeps most of the stimulus intact while reducing financial-stability risks and bank collapse probabilities. It is a pragmatic middle ground: not a full negative rate regime (which would maximize stimulus but cripple banks), nor a return to corridor systems (which would sacrifice stimulus for discipline).

How it works: the mechanics

Suppose the ECB sets the policy rate at -0.5% and introduces a tiered system with a threshold of 30% of reserves per bank. For any given bank:

• The first 30% of its average reserve balance earns 0% (neutral rate).
• Any reserves above that 30% threshold earn -0.5% (the penalty rate).

A bank with 100 units of reserves earns:

• 30 units × 0% = zero interest.
• 70 units × -0.5% = -0.35 units (a charge).

Contrast this to a pure -0.5% regime (where all 100 units are charged): the bank saves 0.15 units, improving its profitability. But the bank still has an incentive to lend out the marginal 70 units rather than hold them at -0.5%.

The threshold percentage is a policy lever. A higher threshold (say, 50%) shields more banks from the negative rate, reducing the stimulus but cushioning profitability further. A lower threshold (say, 15%) intensifies the stimulus but risks bank distress. Central banks adjust based on how much pressure they see on bank margins and lending supply.

Why the ECB chose tiering

The European Central Bank introduced tiered reserves in September 2019, before the COVID-19 pandemic, as it maintained a negative interest rate policy despite weak eurozone growth and persistent low inflation. By 2018–2019, banks were complaining loudly: their net interest margins were compressed, profitability was weak, and some threatened to reduce lending or even close retail branches.

The ECB’s tiering system offered an exemption on a threshold of around 10% of required reserves (later adjusted), allowing banks to hold a portion of their mandatory reserve balances at zero rate rather than -0.5%. This was gentler than a full positive rate (which would completely neutralize the stimulus) but kinder than forcing all banks to absorb the full negative charge.

The move was controversial. Critics argued that any exemption weakened the stimulus and that the ECB was caving to bank lobbying. Supporters countered that a middle path preserved both the monetary-stimulus signal and the health of the transmission mechanism—if banks are too weak, they cannot lend even if policy rates are low.

The transmission chain and tiering

Monetary policy works through a transmission chain: the central bank sets a policy rate, banks pass it through to lending and deposit rates, firms and households respond by borrowing and spending more. Tiered remuneration is meant to keep this chain intact.

Without tiering, a deep negative rate on all reserves might force banks to:

• Raise deposit rates (impossible; depositors would withdraw), or
• Cut lending rates below profitability, or
• Reduce lending volume to protect margins.

Any of these would break the transmission chain. Tiering preserves it by allowing banks to earn a reasonable margin on a tranche of reserves, freeing them to lend at lower rates on the marginal reserve. The stimulus reaches the real economy instead of being dissipated in bank distress.

Who else has used tiering

Switzerland’s central bank (SNB) adopted tiering in 2022 as it shifted to negative rates and faced mounting complaints from banks. Japan has never gone full negative rate (only -0.1%, and heavily hedged), so tiering was less necessary. The Federal Reserve, notably, never adopted negative rates and thus never needed tiering as a workaround.

Most central banks that experimented with negative interest rate policy found themselves pondering tiering at some point—the logic is hard to resist if the bank sector shows genuine distress. Yet tiering is also a sign that pure NIRP has hit practical limits; it is a visible compromise between stimulus and financial stability.

Trade-offs: stimulus versus stability

Tiering sits on a knife’s edge. Too generous an exemption (high threshold percentage), and the stimulus weakens—banks can shield themselves from negative rates, reducing the incentive to lend and spend. Too stingy an exemption (low threshold), and banks suffer, risking credit contraction or failure.

There is also a fairness argument. Banks with high demand deposits and large reserve holdings benefit more from tiering than banks specializing in lending. The exemption inadvertently rewards passive balance sheets, potentially favoring large, retail-heavy banks over smaller, lending-focused lenders.

The mechanism also adds complexity. A pure corridor system is simple to communicate and administer. Tiering introduces a second moving part (the threshold level), which can confuse markets and require frequent recalibration.

The post-2023 reversal

As inflation resurged in 2022 and central banks raised rates above zero, tiering became moot. The ECB ended negative rates in 2022, and with them, the need for tiering. Most tiered systems were quietly wound down or converted back to standard floor systems.

The experiment revealed that tiering was never an ideal solution—it was a stopgap that kept the economy on life support while central banks grappled with a deflation that conventional policy could not cure. Once positive real rates returned and inflation became the threat, tiering vanished from the policy toolkit.

See also