While examining the macroeconomic effects of increased government control of the informal sector, this paper develops a two-sector general equilibrium model featuring matching frictions and worker-firm wage bargaining. Workers search for jobs in both the formal and the informal sector. We analyse the impact of higher punishment rates and a higher audit rate on labour market performance. We find that a higher punishment rate reduces the size of the informal sector and reduces unemployment. A higher audit rate has an ambiguous impact on unemployment, and may actually increase the size of the underground economy.