I believe it depends on the financial capabilities of the parents or how things are with the family. In our country most of the time the parents pay for the college education of their children. My parents paid for my education. In return I am giving them monthly allowance. My parents always says that they don't need the money that I am giving, but since I am earning now, It is my decision to do it. They can use it in buying what they want. It's just one way of showing that it is my turn now to do something for them.