Debates about the conduct of monetary policy have evolved over time from “rules versus discretion” to “policy rules versus constrained discretion.” We propose a metric to evaluate monetary policy rules that are consistent with constrained discretion by calculating quadratic loss ratios, the (inflation plus unemployment) loss in high deviations periods divided by the loss in low deviations periods, with policy rules with higher loss ratios preferred to rules with lower loss ratios. The central results of the paper are (1) economic performance is better in periods of low deviations from policy rule prescriptions than in periods of high deviations from policy rule prescriptions for the vast majority of rules, and (2) rules with larger coefficients on the inflation gap than on the output gap are preferred to rules with larger coefficients on the output gap than on the inflation gap. These results are robust to policy lags between one and two years, different weights on inflation loss than on unemployment loss, various definitions of high and low deviations periods, fixed and time varying neutral real interest rates, fixed and time-varying inflation targets, and measuring economic slack by either the output gap or the unemployment gap. We conclude that (1) the Fed should “constrain” constrained discretion by following a rule that responds more strongly to inflation gaps than to output gaps and (2) this type of rule should be added to the Fed's semi-annual Monetary Policy Report.

随着时间的流逝，关于货币政策行为的争论已经从“规则与自由裁量权”演变为“政策规则与约束自由裁量权”。我们提出一种度量标准，通过计算二次损失率（高偏差时期的（通货膨胀与失业）损失除以低偏差时期的损失）来评估与受约束的自由裁量权相一致的货币政策规则，而优先选择高损失率的政策规则损失率较低的规则。本文的主要结果是：（1）对于大多数规则而言，与政策规则规定之间的偏差较小的情况下的经济表现要好于与政策规则规定之间的偏差较大的时期，（2）通货膨胀缺口系数大于产出缺口系数的规则优先于产出缺口上系数大于通货膨胀系数的规则。这些结果对于一年到两年的政策滞后，通货膨胀损失与失业损失的权重不同，高低偏差期间的各种定义，固定和随时间变化的中性实际利率，固定和随时间变化的通货膨胀目标以及用产出差距或失业差距衡量经济松弛。我们得出的结论是：（1）美联储应通过遵循对通货膨胀缺口比对产出缺口反应更强烈的规则来“约束”约束的自由裁量权；（2）这种类型的规则应添加到美联储的半年度货币政策报告中。这些结果对于一年到两年的政策滞后，通货膨胀损失与失业损失的权重不同，高低偏差期间的各种定义，固定和随时间变化的中性实际利率，固定和随时间变化的通货膨胀目标以及用产出差距或失业差距衡量经济松弛。我们得出的结论是：（1）美联储应通过遵循对通货膨胀缺口比对产出缺口反应更强烈的规则来“约束”约束的自由裁量权；（2）这种类型的规则应添加到美联储的半年度货币政策报告中。这些结果对于一年到两年的政策滞后，通货膨胀损失与失业损失的权重不同，高低偏差期间的各种定义，固定和随时间变化的中性实际利率，固定和随时间变化的通货膨胀目标以及用产出差距或失业差距衡量经济松弛。我们得出的结论是：（1）美联储应通过遵循对通货膨胀缺口比对产出缺口反应更强烈的规则来“约束”约束的自由裁量权；（2）这种类型的规则应添加到美联储的半年度货币政策报告中。通过产出缺口或失业缺口来衡量经济松弛。我们得出的结论是：（1）美联储应通过遵循对通货膨胀缺口比对产出缺口反应更强烈的规则来“约束”约束的自由裁量权；（2）这种类型的规则应添加到美联储的半年度货币政策报告中。通过产出缺口或失业缺口来衡量经济松弛。我们得出的结论是：（1）美联储应通过遵循对通货膨胀缺口比对产出缺口反应更强烈的规则来“约束”约束的自由裁量权；（2）这种类型的规则应添加到美联储的半年度货币政策报告中。