And if the parks and streets are safer, wouldn’t that convince more people to live in those urban neighborhoods (say, instead of the suburbs)? Doesn’t that ultimately have a green effect? I don’t know how it all tallies up, but surely there are a few marks on the positive side of the dog externality ledger.

Richard Kayman’s paean to dog walkers describes my experience perfectly:

I am not a dog person myself, but I am deeply appreciative of well-managed dog parks because in many urban neighborhoods, dog owners are some of the only regularly walking people in a community — many neighborhoods outside of the inner core of Washington are dominated by automobiles and there is relatively little positive pedestrian activity on often empty sidewalks.

Dog walkers contribute positive activity not just to streets and sidewalks but to parks. It’s very easy for a park to devolve into a dangerous place. One technique for people committed to disorder to keep people (especially families and children generally) out of parks is to break a lot of bottles — broken glass keeps a park free of children, making it easier to conduct illicit business and activities.

My neighborhood isn’t the world’s best, but nor is it the world’s worst. After dark, the streets fill with dog walkers. A couple per block, at least. In the winter, they’re the only people on the streets. Without them, the neighborhood would be lot emptier, and the streets would feel a lot more forbidding. Placing a couple of poodles — and my neighborhood has a lot of poodles — on the landscape really does wonders. Developing neighborhoods should give some sort of tax credit for dog ownership.

Actually, my area is doing the next best thing. The city is building a big park/open air drug market near my house. At least, that’s the joke. But the design is smart: It’s got a big dog park, in addition to a community garden and some playgrounds. And if the streets are any indication, the dog park will be used, which means the park will be used, which means the plan might work out after all. The blogosphere is oddly thick with cat owners, but this is just one more reason dog people are better than cat people.

Here’s a partial quote from the longer post/article by Ryan Avent:

The value in economically dynamic cities is the people that populate them. Where once, firms would pay high land prices to be near coal deposits or harbors, based on the economic advantages those amenities conferred, they now pay high land prices to be near talent. This yen to concentrate in particular areas has a number of dynamics. Firms want to be near customers and clients. Workers want to be near firms. Firms want to be near workers. Where there are lots of firms and workers, there will also be businesses serving those workers — in business and in the provision of consumption opportunities — and those services attract additional firms and workers. Everyone wants to be where everyone is, and it’s tough for anyone to go somewhere else because somewhere else is where people aren’t.

The result is an urban geography that’s very lumpy. People clump together, because there are gains to doing so.