Assumptions
The data in these pages comes from a variety of sources. These are listed on the pages concerned, usually in captions to the tables and charts. Please note that different datasets may have been calculated in different ways, and that some values are approximate or estimates. If you are using the data for research, therefore, we advise checking the original sources.
We have taken data for the year 2017 where possible. Some data providers haven’t yet released data for more recent years; and 2020 and 2021 would be unrepresentative because of Covid’s effects on factors such as labour, pollution, production, and consumption.
World population in 2017 is taken as 7.509 billion. Source: World Bank, https://data.worldbank.org/indicator/SP.POP.TOTL .
Biases
I have tried to use only sources that I think reliable. In particular, I am wary of commercial sources. So some bias-checking is in order. Here is the start of a list of bias checks.
Our World In Data: https://mediabiasfactcheck.com/our-world-in-data/