How accurately do we know the number of people on Earth?

Question

To the nearest billion? 0.1 billion? 0.01 billion?

There are censuses and estimations of course, but they can't possibly count everyone.

What about people who live in undiscovered tribes?

What about people in very rarely visited nearly pristine tribes? Do they send someone out to bother them for the first time in years just to check how many there are?

Do estimations include take this into account or not?

There can't be too many of them, all the people living in 3000 B.C. for example was ~0.1 billion, and that was when many had already found farming.

What happens when there is a war or drought like the Rwandan genocide, they can't keep track of how many people die.

What about illegal immigrants, the homeless, the really poor, people without a permanent place of living, people who are less likely to be counted in a census.

Does the world pop estimate include them?

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hopefully there will be enough scientifically-minded people here to answer -- the other categories suck..

Answer 1

great question!!

Answer 2

There is definitely some margin of error and yes, always people are dying off and new babies are coming in, so the figure will never be static.

Since the total population being talked of is estimated as about 6 or 7 billion, an error of say 0.1 billion will not have much imact on the statistics, though in absolute terms that is the population of a few countries!

Answer 3

'You can ask all the people in China to jump all at once and calculate the Geological tremor in USA then repeat it in India.
The tremor intensity will be directly related to the total mass of the Chinese people and add it to India's data. Then, get the average weight of all Chinese and Indian population by measuring at least one person for every town and average it for every province. Then, you average the whole country and add it to India's average and average it again. Now, Get the population of the two countries and find it's ratio between the USA population and repeat it in Europe's population. That will figure out the number of population in the world. Let the small countries your margin of error.

Answer 4

I would guesstimate the error is about 0.5% to 0.8%, or about 30 million to 55 million people.

Answer 5

seven billion.