Does installing an alarm system in your home have an effect on the number or results of burglaries?
I am about to buy a house with an alarm system installed, with a siren/flash light on the front wall. I hate it when I have to enter a house like that, because I fear forgetting or mistyping the code, or arming the system when I want to disarm it, or just being too late because my hands were full.
If I would leave the system permanently disarmed, should I expect an increase in the number or effect of burglaries? I think the number will probably stay the same: thieves can't know the system is not armed (or even fake). Once they get in they might have more time to steal stuff, but I think the psychological effect of a burglary is the fact that they entered your house, not how long they stayed there.
I have read that car alarms don't make much of a difference, but what about house alarms? One indicator is the fact that insurance premiums here in Belgium don't seem to depend on an alarm being installed.