Fare Evasion is it a youth issue?

Fare evasion is not a new subject, it is often written about in the popular press. A person only need stand at a local station for any period and it can be observed. It is possible to unobtrusively observe it at unwstaffed gates as well as staffed gates. On almost a daily basis on my way to and from the city, I have observed people committing the offence. Each time I observe someone commiuing the offence, I consider why is something not being done? I wonder why is it that station employees stand in pairs chatting at certain gates, while other gates remain un-staffed and offer easy options for people to commit the offence?