An illegal market is an economic activity carried out outside government-sanctioned channels.
Underground markets sell illegal goods and services, legitimate goods and services to avoid taxes, or both.
Examples of underground markets include the sale of illegal drugs, weapons, human trafficking and the illegal wildlife trade.
Underground markets can have a negative impact on the economy as activities are not reported and taxes are not levied on transactions.
Underground markets do provide some benefits, such as creating jobs for those who may not be able to find work in traditional markets, and providing access to medicine and health care for people who might not otherwise have access.