It probably isn't. There is a known problem at the moment of ASB in Town Green around the new Co-op (a converted pub probably more use to the community than the rubbish pub that was previously there; if you're in Town Green and want a nice pub the one to go for is the one by St Michael's Church) and the Police have stated it's kids from closer to Liverpool travelling up by train (without paying, obviously) rather than local kids. That doesn't go to say there isn't any ASB from local Aughton kids ever, of course there is, but it's not exactly a hive of it.
It would probably be solved if Merseyrail was to install gatelines on all the stations where it's physically possible. They are staffed for the full period of service, so the gatelines would always be closed, and would also deal with "but the ticket office bloke wasn't there" fare dodgers. A similar problem exists based on the South London DOO commuter lines, where most stations are not gated, and similarly gating them would go a long way to fixing both on-board and related ASB.
What's happened to the rent-a-thugs who were meant to have improved things in the evenings from the slightly rough state of things in the 90s? Are they concentrating on penalty faring and feet on seats? (Not that those things shouldn't be dealt with, but ASB that is making people avoid using the system should be higher priority).