Empirical evidence suggests that bank lending rates are downward rigid: banks tend to adjust their rates more slowly and less completely to short-term market rates decreases than to increases. We investigate the macroeconomic consequences of this downward interest rate rigidity by introducing asymmetric bank lending rate adjustment costs in a macrofinance dynamic stochastic general equilibrium model. Calibrating the model to the euro area economy, we find that the difference in the initial response of GDP to positive and negative economic shocks of similar amplitude can reach up to 25%. This means that a central bank would have to cut its policy rate much more to obtain a symmetric medium-run impact on GDP. We also show that downward interest rate rigidity is stronger when policy rates are stuck at their effective lower bound, further disrupting monetary policy transmission. These findings imply that neglecting asymmetry in retail interest rate adjustments may yield misguided monetary policy decisions.

经验证据表明，银行贷款利率是刚性向下的：银行倾向于更缓慢地、更不完全地将利率调整为短期市场利率下降而不是上升。我们通过在宏观金融动态随机一般均衡模型中引入非对称银行贷款利率调整成本来研究这种利率下行刚性的宏观经济后果。将模型对欧元区经济进行校准，我们发现GDP对幅度相似的正负经济冲击的初始反应差异可达25%。这意味着中央银行将不得不大幅降低政策利率，才能对 GDP 产生对称的中期影响。我们还表明，当政策利率停留在有效下限时，利率下行刚性更强，进一步扰乱货币政策传导。这些发现意味着，忽视零售利率调整的不对称性可能会导致错误的货币政策决策。