This is an interesting topic. Here in the UK, I think most cats are allowed outside, unless they live in city centres. I have noticed, whilst on holiday in America, that I hardly ever see cats outside. My cat, Sadie, has a cat flap, so she pops in and out into the garden during the day, but I always keep her safely in at night time, from about 9 pm. She doesn't wander at all, just enjoys sitting in the fresh air, watching bees and butterflies, and patrolling her "territory", but I do know lots of cats do wander and there is always a risk. I think the ideal would be a secure garden.