We developed a class of dynamic stochastic general equilibrium models with nominal rigidities to investigate the importance of default risk awareness in developing and implementing monetary and fiscal policies. We introduced default risk in the model and analyzed two policies: exact policies and false policies. The exact policy includes optimal monetary and fiscal policies as well as policy authorities who are aware of default risk. The false policy includes optimal monetary and fiscal policies as well as policy authorities who are unaware of default risk. We calculated the coefficients of simple rules that are a class of Taylor rules and a class of the Bohn rule. We found that there is no distinction on simple rules between the exact and false policies if the interest spread in the steady state is low. However, if the interest spread is high, policy authorities should not stabilize inflation and minimize the premium difference. We calculated welfare costs under the two policies. If the interest spread is low, there is a large difference in welfare costs between the two policies, and if the spread is high, the difference between the welfare costs is further increased. If policy authorities are unaware of the default risk, they introduce a stricter policy that generates significant welfare costs. If the interest spread is high, policy authorities should be aware of the default risk.

中文翻译：

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违约风险意识在执行货币和财政政策中的重要性

我们开发了一类具有名义刚性的动态随机一般均衡模型，以研究违约风险意识在制定和实施货币和财政政策中的重要性。我们在模型中引入了默认风险，并分析了两个策略：精确策略和错误策略。确切的政策包括最佳的货币和财政政策以及意识到违约风险的政策机构。错误的政策包括最佳的货币和财政政策，以及不了解违约风险的政策机构。我们计算了简单规则的系数，这些简单规则是一类泰勒规则和一类博恩规则。我们发现，如果稳定状态下的利差很低，则精确策略与错误策略之间没有简单规则的区别。但是，如果利差很高，政策主管部门不应稳定通货膨胀并使保费差额最小化。我们根据两项政策计算了福利费用。如果利差低，则两个政策之间的福利成本差异较大；如果利差高，则福利成本之间的差异进一步增大。如果政策主管部门不了解违约风险，则会引入更严格的政策，产生大量的福利成本。如果利差很高，则政策机构应意识到违约风险。福利费用之间的差额进一步增加。如果政策主管部门不了解违约风险，则会引入更严格的政策，产生大量的福利成本。如果利差很高，则政策机构应意识到违约风险。福利费用之间的差额进一步增加。如果政策主管部门不了解违约风险，则会引入更严格的政策，产生大量的福利成本。如果利差很高，则政策机构应意识到违约风险。