In New Zealand, they say it is illegal to leave a child under 14 at home alone. However what does the law practically say about leaving children under 14 home alone? Information on the CYFS website says it is against the law without making "reasonable provision for their care and supervision". But I think one person's reasonable is another's never ever, so CYFS' explanation goes on to say it depends on how long and how often they are left alone. Then it says this: "Older children, who are still under the age of 14, are generally not sufficiently mature to be left without adult supervision for more than a short time. They're also not old enough to be left alone on a regular basis." OK, but how long is too long and how regular is too regular? Then they add confusingly that if we must leave an older child who is still under 14, they need to make sure the kid knows who they can contact if there is a problem, possible emergencies and what to do and that they feel "confident about being left alone". On the other hand,Youth Law says more definitively parents cannot leave under 14 alone at home without making "reasonable provision" for their supervision and care. "This usually means making sure we have a babysitter," they say, adding that some over 14-year-olds aren't mature enough to be left alone and leaving them alone could "amount to neglect or abuse".
However I believe it is more than negligence or child abuse because if something bad happened, legal liability would be the last of our worries.