If we consider a 16 years boy as child, than it will be a matter of debate. If a 14 years boy help his father in his shop or farm, you shouldn't consider it as child labor. If there are no earning members in the family (father dead, only mother and younger brothers /sisters) then elder child might involve himself in money making job. But no doubt, the task or job must be according to his physical capacity. We shouldn't burden on him. He is just trying to help his family. We should help him as much as possible.