The History of Population Estimates

Although population estimates and their consequences can be seem as a fairly recent and trendy topic to study, we have been counting people for thousands of years. However, what has differed over the years is the reasons why population data has been collected...

The first census known to have been recorded was by the Babylonians in 3800 B.C. and not only counted the number of people, but also the number of livestock and quantities of food such as milk and honey (Census, 2011). This suggests that the Babylonians were quite forward thinking when it comes to environmental concern, considering the amount of food and the number of mouths to feed - a problem we are still trying to work on to this day!

The first census completed in England was the Doomsday book in 1086. It was ordered by William the Conquer, whom invaded the country in 1066. The reason behind the survey however, was not knowledge but money, as the purpose of the survey was for the King to find out how much tax he was owed from settlements across England. The book is now however a window into the population of the past and also providing extensive knowledge about settlements and landscapes across England in the 11th century.

To discover more about the Doomsday book and delve into the history of your town or village visit: http://www.nationalarchives.gov.uk/domesday/

The first official UK census as we know it today was commissioned in 1801 and was prompted by the work of Malthus (a big name in population studies!) In his book 'An Essay on the Principle of Population' (1798), he argues that population will increase exponentially whilst food supply will increase arithmetically causing famine and poverty across the world (Malthus, 1798). In light of this, the 1801 census was commissioned in the UK and has been undertaken every 10 years since. This shows how concern for the capacity of the environment prompted the need to record the number of people within the country.

The Mid 19th Century marks the date when a mutual agreement was reached about the history of the world and continental population growth after 1650. This consensus was based on 2 publications about population estimates: "Studies in American Demography" by WIllcox (1940)  and "World Population: past Growth and past trends" by Carr-Saunders (1936) (Caldwell and Schindlmayr, 2002). These estimates were later legitimised by the UN Population Division in 1951.

Since then, the UN Population Devision has been constantly monitoring population changes across the world in different publications. This then brings us back to the most recent statistics by the UN that world population will increase to between 9.6 billion and 12.3 billion in 2100 (Gerland, 2014). The reason the UN undertake population estimates is stated on their website:

'Over the years, the Division has played an active role in the intergovernmental dialogue on population and development, producing constantly updated demographic estimates and projections for all countries, including data essential for the monitoring of the progress in achieving the Millennium Development Goals...' (http://www.un.org/en/development/desa/population/about/index.shtml)

It is clear that the UN is putting these projections into context by applying the estimates to targets for the future improvement. This is the main purpose of population research nowadays, as it is no longer just about knowing how many people are on this Earth, it is about planning the future population. With the number of people growing, it is critical to think about the future global environment and plan for a greater number of people on earth.