A fantastic economics paper by Corey (2009) explores the behaviour of ghosts and determines that ghosts are rational actors and, where possible, refrain from killing living entities.
As Corey (2009, p.1) states in his abstract: “If ghosts are rational economic actors then ghosts would have no incentive to severely disturb the living population as it is likely that the costs to the ghost of killing an individual outweigh the benefits. When a ghost kills an individual then that individual could then conceivably turn into a ghost and, as a ghost, annoy its phantom killer for an even longer time period than if left alive. A ghost would be much better off being annoyed by a living entity for the comparably short period of time of that person’s lifespan rather then to kill that individual and, by doing so, inducing that person to seek retribution in the afterlife.”
What is key to Corey’s conclusion is the assumption that ghosts use a cost-benefit analysis in their decision making. Corey (2009, p.3) begins by highlighting that people make decisions as a result of performing a cost-benefit analysis. If the benefits of an action outweigh the costs, then we decide to perform that action. Because ghosts used to be living entities, we must assume that they would also behave in an economically rational way and use a cost-benefit analysis when making decisions.
Corey (2009, pp.7-8) refers to various different paranormal literature to support the belief that ghosts behave rationally using a cost-benefit analysis. For example, European folklore suggests that ghosts are attracted to travelers because they usually travel alone, indicating that ghosts choose to interact with low cost targets. Also, physical interactions between ghosts and objects and/or people are rare. Paranormal researches believe this to be the case because such interaction requires an extreme amount of energy. Thus, ghosts avoid actions with high costs. Moreover, when ghosts appear to people, they often do so with parts of their body (such as their feet) missing. Arguably, this is because the ghosts must compromise with the amount of energy that they are using to manifest themselves physically. Subsequently, it is more common for ghosts to make their presence known through the use of electrical equipment because, as it is believed, paranormal energy can interact with electrical equipment at a lower cost than through physical manifestations. Furthermore, spiritual energy commonly manifests itself by taking on the appearance of ‘ghost orbs’, these are spherical balls of light frequently pictured in cemeteries and other haunted places. Again, it is believed that forming these spheres is quite a low cost alternative for ghosts in comparison to a full physical manifestation. Thus, it seems that a ghost’s behaviour is dictated by a cost-benefit analysis.
Resultantly, ghosts will use a cost-benefit analysis when deciding to kill you and conclude that the costs outweigh the benefits. The average human lives for less than a hundred years but the lifespan of a ghost is eternal. Thus, if a human is annoying a ghost then it is best for the ghost to accept this annoyance for what is likely to be, at the most, one hundred years rather than kill the person and have them come back as a spiritual entity and seek revenge for eternity in the afterlife. Of course, this does mean that all ghosts behave rationally and are safe to be around. Ghosts, like humans, could be good or bad. Most ghosts behave rationally and do not kill or hurt humans, but there may be some bad apples that will risk suffering your eternal attempts to irritate them in order to kill you.
Corey (2009, p.11) backs up his theory with empirical evidence which suggests that out of 120 ‘true’ accounts of human-ghost interaction, not a single one resulted in the death of the human. In 116 out of the 120 cases, the ghost acted benevolently or in a detached manner, without causing harm to any living person. In the 4 cases where ghosts inflicted injuries to living people, it was only because the living had intruded on their environment. In one case a ghost slapped a person, two other cases involved people being held down and the last case reported that a ghost sexually assaulted a female. But no killings.
Corey, J., (2009), The Rational Ghost: Using Basic Economic Principles to Explain Ghost Behavior, Presentation at the meeting of Morgantown Paranormal Conference.