Due to sensible points made in the comments, I have reworded and clarifed my question.

I am trying to setup a world where due to reasons (mystical or alien) people have been going missing with no information over a period of time. They just seem to vanish without leaving any traces behind (no one sees them go missing). Eventually various governments/international agencies will pick up on these disappearances and conduct their investigations.

How many people would need to disappear in a year across the world for this to eventually be noticed (preferably after at least 1 year)?

**While I am aware that police would get involved with any missing persons case, i'm more curious about how many would need to go missing before its seen as unnatural and possible measures would be taken by countries worldwide (im specifically looking for governments changing polices or separately investigating this not just journalists reporting it or social media outcries)


marked as duplicate by SZCZERZO KŁY, Renan, kingledion, Tim B II, Separatrix Aug 29 '18 at 13:03

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    $\begingroup$ Hello casualcoder, check those questions related to yours: - worldbuilding.stackexchange.com/questions/23146/… and - worldbuilding.stackexchange.com/questions/87507/… $\endgroup$ – Liquid Aug 29 '18 at 9:49
  • $\begingroup$ 300 people per year, evenly distributed over the globe, will never be noticed. It will result in a number of cold cases... but there will never be any particular pattern visible unless you — as the author — make a pattern appear. The question then is how to make people realise this is a global phenomenon. I would suggest that there is a conference of some sort, where people from many different regions get together. Then, over a beer in the evening, someone says "Y'know... I have the darndest cold cases...". "Huh... you too?". $\endgroup$ – MichaelK Aug 29 '18 at 9:52
  • $\begingroup$ @Liquid I have seen those questions, but they look at targeted abductions and how to remain unnoticed, im looking at a case where people are randomly chosen $\endgroup$ – Karan Shishoo Aug 29 '18 at 9:53
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    $\begingroup$ Remember that police jurisdictions across the globe do not casually talk to each other, nor do they hook up their databases to let the computers compare notes. And someone in — say — a US state will never be allowed to look at the police records in some Chinese regional province without tons of paperwork. So you need to create a plot facilitator where people get together in an international meeting and accidentally get talking. $\endgroup$ – MichaelK Aug 29 '18 at 9:55
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    $\begingroup$ @casualcoder You must engineer that kind of event, because otherwise people will never notice the globality of the occurrence. $\endgroup$ – MichaelK Aug 29 '18 at 9:57

I changed my comment to an answer

In US it's 2300 missing people every day. 16000 for more than a year in UK alone. 300 worldwide is less than only children only in the UE for one day. To put it differently 250000 children are reported missing in UE every year. There are some patterns to that (sex slavery is assumed around 2 millions trafficed kids a year in UE alone).

There are some trends in disappearance. For the governments to take notice it's something new I would assume the number need to be in ten of thousands (for one country) with a modus operandi so uncanny it would be put in reports and then formed into category.

Missing people when no one sees them disappear (and there are no records of mental problems, relationships issues or criminal background) are called (in polish) "walk-outs". When people just decide to leave their old life behind. There is a category for that. So those disappearances would need to leave some strange trace it would not be put in those "walk-outs".

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    $\begingroup$ I know that in the UK around 98% of people reported missing are found again within a week meaning that 'only' 3200 actually go missing with no trace. It depends on how the jurisdiction that you are refering to defines missing for example a senile older person who lets themselves outside of their home and falls asleep under a bus shelter and later found is recorded as missing in the UK. $\endgroup$ – Sarriesfan Aug 29 '18 at 11:31
  • $\begingroup$ @Sarriesfan I assume there is also a lot of older people with dementia who go out and are never found. The vide spectrum of people who can go missing, or lack of focus for particular group, in OP question can just up every other group by few so nothing can be noticed. You would need to bump those number by a large amount (or create new trend) for people to start asking questions. $\endgroup$ – SZCZERZO KŁY Aug 29 '18 at 12:52

For anything to become globally supsicious, it should be statistically significant. Which means basically the number of disappearance per year (or month, week) should be outside of statistical margin errors. I don't know much about statistics, though, but we can try some things.

Of course, each governemental organisation will probably only look at its own country missing reports at first, and I guess number of missing reports (or percentage of population) vary from one country to another, so some countries might have a hint before some others.

Let's take USA for example, because I easily found some numbers online: if we compile the monthly entries of 2014, it gives a mean of 50k per month, with a standard deviation of 11.5k. So, I guess a monthly report exceeding mean+2(or even 3) standard deviation would be quite alarming, which would give a monthly report of around 80k missing people.

The ressource also report yearly entries since 1990, so that could also give you a good idea of the numbers that could be alarming.

I would say extra disappearances exceeding several times the standard deviation would be alarming to the authorities, but I would gladly be corrected by some statistic expert.


In real world, in Russia alone, about 100 000 people disappear without trace every year. That makes an average of 100 per region per month. For govs to take notice that something is amiss, this number must be notably exceeded, like, 500 in one month in one region, or extra 30 000 across country.


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