Cats, Dogs and freakonomics

Freakonomics is basically about the use of ideas from economics to investigate how incentives shape the way people act—including perverse incentives that trap them into behaviour that benefits nobody, including themselves. I picked up a copy of the book in our charity shop recently, and I've been thinking about the ways in which these ideas apply to the world of animal welfare.

Lots of the issues we face are very clearly freakonomics-type problems:

• The person on very low income who buys a £2,000 puppy and doesn't have £20 to pay for vaccinations, or £55 to pay for neutering.
• Whether it's better for rescues to charge an adoption fee and lose some potential adopters, or charge nothing and risk rehoming to people who can't even afford the cost of a single veterinary consultation if the animal gets ill or injured.
• If rescues don't rehome to people who can't afford veterinary treatment, what happens when those people get animals through other channels?
• Does provision of low-cost, or free veterinary treatment for pet owners on low income mean some of them acquire more animals until they still can't afford treatment costs? What proportion of them?
• Pet owners who can't afford the cost of spaying and are then faced with the cost of a caesarian or emergency hysterectomy, which can be at least five times as expensive.
• Cat owners who put off spaying because of the cost and end up with five cats to feed instead of one.
• Pet owners who simply assume free or low-cost veterinary treatment will be available in an emergency. What proportion of pet owners does this apply to?
• Does provision of low-cost spay/neuter reduce the numbers of unwanted pets? It seems obvious that it should, but maybe it's not true for all species—for example most pet rabbits seem to be acquired from pet shops, and the primary reason for them becoming unwanted seems to be lack of knowledge about the amount of work and expense involved in keeping them. (It is very important to spay and neuter rabbits in order to be able to keep them in pairs which is vital for their individual welfare.)
• What effect does education about spaying and neutering have on the proportion of dogs and cats belonging to pedigree breeds? Are the effects the same for both species? 
• How do you avoid education replacing one problem by a different one? For example discouraging purchase of exaggerated pedigree dogs leading to a fad for crosses which may have their own problems.
• Fads for particular breeds (during my lifetime German Shepherds, Border Collies, Lurchers and now Staffordshires have all suffered the effects of excess popularity, or popularity for the wrong reasons.)
• Breeds becoming attractive to certain types of people precisely because they have a bad reputation.
• Is there a way to encourage pet owners who would otherwise be a drain on the resources of animal welfare societies to contribute by taking part in fundraising, or other useful activities, thus potentially changing a vicious circle into a virtuous one?

Update

Checking the link to the Freakonomics site, I came across this economics blog post which is horribly relevant to the problem of the family with maxed-out credit cards and a sick pet who won't make it through Christmas without treatment.