Investigating of Underground Economy by Using Currency Ratio and Gap Between Expenditure and Income of the Family

Underground Economy is a series of value added activities which is not defined in the frame of formal economic. Private activities, private organizations and those kinds of market activities which, in some way, are not discovered by officials, totally, are making black or informal economic. Underground economy includes four sections: family, informal, irregular and illegal. The nature of unclearness of black economic, make it hard to estimate and study the economy, because of these, most of current measuring methods are indirect measuring of thise activities which are accompanied by limited assumptions. Through this research, in spite of considering different methods of measuring black economy, we estimate the amount of underground economy, using "currency ratio" and "Gap between expenditure and income of family". The gap between expenditure and income of family method is based on discrepancies between expenditure and income of families which is not reported in the national accounts. In "currency ratio" method we measuring the size of underground economy based on exchange of currency.