Why do sale of used goods do not add to income of a country in a particular year? If you think of income as the inflow in your bank account. All outflows are just expenditures. So I think of income as how much stuff can someone buy in a particulate year. Lets say person A bought a football for 50 dollars. Someone's income is increased by 50 dollars. So currently total income of society is 50 dollars in the current year. Now the guy who bought it sells it for 30. His income in this year is 30. All outflow is expenditure, in other words you are making use of your income. It does not really reduce income. So total income of society in this year should be 50 + 30 = 80? What is wrong with this logic?