An example of income that would be included in the underground economy but not included in the gdp is

GDP, or Gross Domestic Product, is typically defined as services, products, goods produced and bought by an national economy in a specific time frame, and is measured comparatively to a time period before. Bitcoin is an example of an underground currency that is not part of the GDP, due to no production of goods or services for the nation and not regulated by government.

Typical demographics data include gender, income and geographic region.