That gated neighborhood thing took me by surprise.
Not any in my area(Eastern MA) ————gated estates,sure,but gated neighborhoods are VERY rare,if there are any at all.
Might be a combination of the two.
Actually a gated neighborhood is not as uncommon as you might think once you get into the countryside. I own a lot in one here in Virginia. Established in the 1960s as a vacation/resort community. 1300+ lots now mostly filled in with houses. Houses range from below $200K to $1 million+ lakeside. Has a lot of amenities inside the community. Run by a HOA, completely fenced, own security, fire, and EMS services. Basic HOA fee: @ $150/month.