I live in a suburb of Philadelphia, PA. My oldest is six, but I intend to teach her how to walk to her friends' houses on her own within the next year or so. Right now the most they've done is play in the yard without me, but I've never had anyone call the cops on me (luckily). This is absolutely a concern of mine, but Pennsylvania actually does not have any laws concerning the minimum age that a child can be left alone. So, even though I do worry that a nosy neighbor might call the cops, I cannot actually face any legal ramifications.