Liquidity Policies in the 21st Century

This proposal explores the optimal design of central bank liquidity policies in a modern financial system characterized by new risks and economic constraints. It is structured around three connected projects, each addressing an aspect of liquidity provision: the remuneration of central bank reserves, the design of lender-of-last-resort policies and the stimulative effect of liquidity injections. Project 1 investigates how central banks should supply and remunerate reserves. The project considers how key frictions—market power, liquidity risks, and balance sheet constraints—affect banks’ ability to transform reserves into deposits. It proposes a model of the deposit market and embeds it into a general equilibrium setup for optimal policy analysis and considers the trade-off with inflation control and fiscal costs. The project will use structural time-series analysis to explain the drivers of rates in the deposit market to obtain moments for calibration. Project 2 examines how lender-of-last-resort policies should adapt to liquidity risks arising from financial hedging. Unlike speculative behaviour, hedging creates liquidity needs for institutions whose solvency has improved. The project will measure these liquidity needs using rich microdata from the FX market and show a connection to lender-of-last-resort borrowing. In theory, it will show policy design must differentiate between hedgers and speculators, balancing generous liquidity support for the former with measures to mitigate moral hazard for the latter. Project 3 explores the stimulative effect of liquidity injections using unique data on payments. It focuses on estimating banks’ marginal propensity to lend (MPL) from liquidity flows, identifying how these vary across banks, and tracing the amplifying effects of payment networks. This project revisits the concept of the money multiplier and aims to show how targeting high-MPL institutions can maximize the stimulative impact of central bank policies