Is everyone looking forward to the forthcoming Halloween? The “All Hallows Evening” is at our doorstep and everyone is preparing for trick-or-treating, brushing off their scary costumes, renting horror movies, carving pumpkins and generally intending to have fun. 
Halloween is the holiday that originated from the Celtic rituals in Ireland and the United Kingdom only to be brought by the migrants to the United States to become an event that can now only be compared to Christmas when it comes to its business potential, overall sales, as well as its economic significance. Last year, American consumers spent about $9.1 billion on Halloween festivities. A paper published in 2017 claimed that the share of more “consumer-focused” Halloween products gradually increased over the years in relation to the share of more “traditional” products. And the most popular Halloween activity is wearing a spooky costume.
Vampires and Halloween
One of the most popular Halloween costumes is to dress up as a vampire. For some reason, people just love Dracula and others of his kind. There are many films, comics and popular literature on and about vampires. And you would be probably surprised to find out that vampires can actually exist and their existence does not contradict modern science!
Well, there are plenty blood-sucking animals found in nature, and even humans need to drink the blood from their own spices sometimes to survive. So, why cannot vampires (the creatures from the myths and legends, as we tend to think of them) exist too? Most scientists use simple math to prove that the existence of vampires is not possible. Their line of argumentation is the following: assume that a vampire needs to feed only once a month (we ignore the mortality rate, since it is irrelevant here). When this process occurs, another vampire is created. If the countdown starts in 1600 AD or some other time around that (on the 1st of January 1600 the world’s population was 536 870 911), then by February 1600 there would be two vampires (one who turned a human into vampire to start with and another one who was a human but became a vampire after the encounter with a vampire). In March 1600 there would be four vampires in existence, and in April 1600 – eight vampires. Therefore, some scientists say, each month the number of vampires doubles and after n months there are 2^n vampires which gives us a geometric progression with ratio 2.
As most of you might know, the geometric progression is increases at a very quick pace and if you sit with a pencil and paper and calculate it for our vampires example, you will arrive to the conclusion that after 30 months there would be no humans left – everyone would be turned into a vampire and the humanity would be wiped out by June 1602. Even if human birth rate is included into our calculations, it remains a very small fraction deaths caused by the vampires and would have prolonged the extinction of human race by just one month. Therefore, some scientists conclude, vampires cannot exist, since their existence contradicts the existence of human beings. This logical proof is of a type known “as reductio ad absurdum”, that is, reduction to the absurd.
However, if one starts digging dipper, everything is not that straightforward. Some works of fiction, Stephenie Meyer’s “Twilight series”, Charlaine Harris’s “Sookie Stockhouse (Southern Vampire) series”, “True Blood” (TV series) as well as Elizabeth Kostova’s “The Historian”, show the world where vampires peacefully co-exist with humans.
In Stephenie Meyer’s “Twilight series” vampires can tolerate the sunlight, interact with humans (even fall in love with them) and drink animals’ blood to survive. Of course, they have to live in secrecy and pretend to be human beings. In “True Blood” TV series, however, a world is shown where vampires and humans live side-by-side and are aware of each other. Vampires can buy synthetic blood of different blood types that is sold in bottles and can be bought in every grocery store, bar or gas station. They cannot walk during daytime, so they usually come out at night. Humans also find use of vampires’ essence – vampires’ blood (called “V”) is a powerful hallucinogenic drug that is sought by humans and traded on the black market (sometimes humans capture vampires with the help of silver chains or harnesses and then kill them by draining their blood). Some humans even seek sex with vampires (vampires are stronger and faster than humans and can provide superb erotic experience). There is a possibility to turn a human being into a vampire, but it takes time and effort.
Let us assume that at the time of the events described in the first book of the series, “Dead Until Dark” (2001), the world’s vampire hypothetical population was around five million (the population of the state of Louisiana in 2001 we arbitrarily use in our calculations). The initial conditions of what I call “a Harris-Meyer-Kostova model” are the following: five million vampires, 6 159 million people, there are organized groups of vampire “drainers”.
Simple calculations yield that the human population will be growing until 2046 when it reaches its peak of 9.6 billion people, whereupon it will be declining until 2065 until it reaches its bottom at 6.12 billion people. This process will repeat itself continuously. The vampire population will be declining until 2023 when it reaches its minimum of 289 thousand vampires, whereupon it will be growing until 2055 until it reaches its peak at 397 million vampires. This process will also repeat itself continuously and we will end up with a cyclical system of human-vampire co-existence.
Under certain conditions, the Harris-Meyer-Kostova model seems plausible and allows for the existence of vampires in our world. Peaceful co-existence of two spices is a reality. However, this symbiosis is very fragile and whenever the growth rate of human population slows down, the blood thirst of vampires accelerates, or vampire drainers become too greedy, the whole system lies in ruins with just one population remaining.
There are more interesting implications to this study: consider for example the organized groups of vampire hunters (“Buffy the Vampire Slayer”) or superhero vampire hunters (“Blade”). The results seem even more interesting and all clues lead to the one simple fact – vampires might co-habituate with humans and modern science cannot refute their existence! Here, you can download a poster explaining my research on this topic and covering different models of vampires and humans co-existence: Poster Vampires exist
Karl Marx, a vampire hunter
You would be surprised to learn that the works of Karl Marx are full of mentioning of vampires (Marx used the vampire metaphor at least three times in Capital). For example, in one of the cases Marx describes British industry as “vampire-like” which “could but live by sucking blood, and children’s blood too”. Here is another quote:““Capital is dead labour which, vampire-like, lives only by sucking living labour, and lives the more, the more labour it sucks”. Marx’s colleague and long-time sponsor Frederick Engels also used the vampire metaphor in his works and public addresses. In one of his works entitled The Condition of the Working Class in England, Engels identifies and blames the “vampire property-holding class” as the source of “all the social troubles”. 
Marx described vampires’ habits, their greediness and their lounging for blood in such a detail that in many cases it crossed the boundaries of the mere metaphor. Although many researchers perceive Marx’s vampires as metaphoric abstract bourgeois bloodsuckers feeding on working people, his knowledge of vampires is very peculiar. In one particular case, when describing Wallachian peasants performing forced labour for their boyars, Marx refers to one specific “boyar” who was “drunk with victory” and who might have been no one but Wallachian prince Vlad (called “The Impaler”) – or Count Dracula himself!
All this is very interesting because the best-known novel of vampiric genre, Bram Stoker’s Dracula, did not see the daylight until 1897, 14 years after Marx’s death. Surely, one can place the Marx’s metaphor in the wider context of nineteenth-century Gothic horror stories which were abundant these days, and of which Marx was a huge fan. On the other hand, one might assume that some of the vampire legends were true and Marx and his contemporaries were aware of that!
Till the last drop!
My research on vampires and humans co-existence (that has been going on for almost 10 years now) is thoroughly described in a popular science book Till the last drop! by “Emily Welkins (my pen name and pseudonym) that shows how vampires became a part of the popular culture. The book also analyzes all possible models of humans-vampires coexistence using mathematical calculations. For the shorter version of the whole story, you can read a paper entitled “How to Stop a Vampiric Infection? Using Mathematical Modeling to Fight Infectious Diseases“. You can also find more on interesting scientific facts about vampires, werewolves, demons (and other spooky topics) in my blog called “Supernaturaleconomics“.
Have a spooky Halloween!!!