No argument here, but I think the delta between a dog and a watchdog is much smaller than the delta between dog and no dog, if what you're worried about is prev

No argument here, but I think the delta between a dog and a watchdog is much smaller than the delta between dog and no dog, if what you're worried about is preventing intruders. I believe that the overwhelming majority of burglaries are opportunistic, and a dog that barks is going to be pretty much sufficient to send the thief down to the next house.