To shed light on the complex and ambiguous relation between shadow economy and labour market outcomes, this theoretical paper introduces tax evasion and undeclared work into the benchmark macroeconomic model of the labour market (the search and matching model). Unlike the related literature, this work assumes that registered firms manage job vacancies in both the formal and the shadow sector (named as “mixed firms”), to maximise the total gains. The unemployed search for a job simultaneously in both sectors and accept the first job offer they receive, while tax audits allow to punish firms that evade taxes and use undeclared work. In this framework, tax audit emerges as the key tool for reducing shadow economy without harming labour market outcomes too much. Tax audit, indeed, has little impact on unemployment and increases the wage (cost) of undeclared work.

为了阐明影子经济与劳动力市场结果之间复杂而模糊的关系，本文将逃税和未申报的工作引入劳动力市场的基准宏观经济模型（搜索和匹配模型）中。与相关文献不同，这项工作假设注册公司管理正规部门和影子部门（称为“混合公司”）的职位空缺，以最大化总收益。失业者同时在两个部门寻找工作并接受他们收到的第一份工作机会，而税务审计则可以惩罚逃税和使用未申报工作的公司。在此框架中，税务审计成为减少影子经济而又不会过多损害劳动力市场结果的关键工具。税务稽查确实