Within an economic model that is free of coercion, it can be assumed that participants interact voluntarily as long as they perceive their gains to be greater than losses: by definition non-zero-sum.  This argument is not original, but it is valuable to note two of its central tenets in the story above.  The first tenet acknowledges that a given commodity can simultaneously hold different values as perceived by different parties.  Such valuation is dictated by circumstantial prioritization, which itself evolves and devolves individually.  The very act of location selection by Mama Dog was indicative of a process of valuation, and the self-tethering of an otherwise free-roaming animal to a specific location was strongly suggestive of a change…