
Tiered reserve systems
Negative monetary policy rates can undermine financial transmission, because they encourage cash hoarding and reduce the profitability of traditional banking. This danger increases with depth and duration of negative interest rate policies. Therefore, some countries (Japan, Sweden, Switzerland, and Denmark) have introduced tiered reserve systems, effectively exempting a part of the banking system’s excess reserves from negative rates. Importantly, a tiered reserve system is now also considered by the European Central Bank for the second largest currency area in the world. Since tiered reserve systems are on the verge of “going mainstream” their impact on asset pricing formulas and quantitative trading strategies deserves careful consideration.