A curious wrinkle in the pet over-population story is that some areas are actually importing dogs from other countries to meet their needs. While it's commendable to bring in dogs from other states that may otherwise be euthanized, it's downright disturbing to import them while dogs are being put down in this country. I think some areas have been so successful in eliminating the stray problem that they are in danger of losing some shelter funding if they don't maintain a certain population. So there's an economic incentive to maintain the status quo.
I don't know enough to speak intelligently about this, but the very fact of importing dogs from other countries for shelters speaks volumes to me. Maybe we need a Nathan Winograd to open our eyes to the reality of shelters.
Here's a link about the importation of dogs.
Dog Laws At Large: Dog shelters import from around the world to fill the need