Do you find that similar dogs live in the same neighbourhood?

I was driving the school bus the morning, and realized that every dog I
seemed to pass was medium size and walking their owner (pulling the human
along at the end of a leash). It made me think: throughout my years of
driving, my routes have taken me through many different neighbourhoods.
Thinking back, I realize that in some neighbourhoods I would see almost
nothing but toy breeds, in others, the smallest dog I would ever see would
be a Bouvier. Another neighbourhood I drive through this year (where the
schools are), virtually every dog I've seen is a "pit bull" type (exact
breeds I'm not sure of). With one other exception, every dog in our
neighbourhood is a purebred. Yet I know neighbourhoods where you could
spend weeks at the dog park playing "Name-that-cross-breed."

It's not just breeds that seem to go by neighbourhood, either. As I dsaid,
the thing that started this thought was watching dog after dog walking their
owners. Yet in my neighbourhood, none of the dogs pull on their leads. I
can only think of one household in my neighbourhood that owns more than one
dog, yet I can think of neighbourhoods where multi-dog households seem to be
the norm.

So what do you think? Do certain neighbourhoods attract similar dog
households? Do you think that it's because the people already have similar
preferences (hence how they became neighbours), or do they see someone
else's dog after they've moved in and think "I want that."?

Marie