This paper studies the impact of political polarization on macroeconomic volatility in a political economy model of optimal fiscal policy. I introduce the distinction between mandatory and discretionary public spending in a model where consumers disagree on the size of the public sector. In the presence of political turnover and political polarization, public policies that affect individual decision-making lead to macroeconomic volatility. I show that the legislative requirements behind the changes in mandatory public spending can reduce macroeconomic volatility caused by political polarization and political turnover. The numerical simulations of the model suggest that in the presence of a binding constraint on the changes in mandatory spending, an increase in the political polarization is associated with an increase in the share of mandatory spending and a decrease in the macroeconomic volatility, consistent with the U.S. data.

本文在最优财政政策的政治经济学模型中研究了政治极化对宏观经济波动的影响。我在消费者不同意公共部门规模的模型中介绍了强制性公共支出和可自由支配公共支出之间的区别。在政治更替和政治两极分化的情况下，影响个人决策的公共政策导致宏观经济波动。我表明，强制性公共支出变化背后的立法要求可以减少由政治两极分化和政治更替引起的宏观经济波动。该模型的数值模拟表明，在强制性支出变化存在约束约束的情况下，