Should we use linearized models to calculate fiscal multipliers?
在新凯恩斯模型中比较线性化与非线性解下的政府消费乘数大小，发现长期流动性陷阱中非线性解对应的乘数远小于线性化解，警告不应在长期流动性陷阱中使用线性化模型计算财政乘数。
Summary We calculate the magnitude of the government consumption multiplier in linearized and nonlinear solutions of a New Keynesian model at the zero lower bound. Importantly, the model is amended with real rigidities to simultaneously account for the macroeconomic evidence of a low Phillips curve slope and the microeconomic evidence of frequent price changes. We show that the nonlinear solution is associated with a much smaller multiplier than the linearized solution in long‐lived liquidity traps, and pin down the key features in the model which account for the difference. Our results caution against the common practice of using linearized models to calculate fiscal multipliers in long‐lived liquidity traps.