[jlhawn]

this isn't necessarily true. While it generates less direct revenue, it increases nearby land value in two ways: 1) business activity which would have taken place on that parcel "overflows" to nearby parcels, ie, the demand for those other land uses doesn't go away and increases prices in the surrounding area. 2) the park provides real value to its users and access to that value also increases nearby ground rents.

[astrange]

Also, it's possible to have businesses in a park (rented sports fields, coffee stands etc). I know a park nearby with a pottery studio in it.

Generally Americans don't think of this because they think public services "shouldn't try to make money" and interpret this as they need to be designed to lose money as hard as possible. So public transit stations have no vending machines and activists are constantly trying to ban them from charging fares.

[vkou]

If we're going to talk about speculative land value, I'll point out that the easiest way to raise it is to ban all future construction.

You are correct that the park provides real value to its users.