The Case for Open-Market Purchases in a Liquidity Trap
论证即使在流动性陷阱中，公开市场操作作为财政政策工具仍能显著提升福利，并用日本数据量化其效果。
Prevalent thinking about liquidity traps suggests that the perfect substitutability of money and bonds at a zero short-term nominal interest rate renders open-market operations ineffective for achieving macroeconomic stabilization goals. We show that even were this the case, there remains a powerful argument for large-scale open market operations as a fiscal policy tool. As we also demonstrate, however, this same reasoning implies that open-market operations will be beneficial for stabilization as well, even when the economy is expected to remain mired in a liquidity trap for some time. Thus, the microeconomic fiscal benefits of open-market operations in a liquidity trap go hand in hand with standard macroeconomic objectives. Motivated by Japan’s recent economic experience, we use a dynamic general-equilibrium model to assess the welfare impact of open-market operations for an economy in Japan’s predicament. We argue Japan can achieve a substantial welfare improvement through large open-market purchases of domestic government debt.