![us population density map one person equals us population density map one person equals](https://i.redd.it/0pdo582kosa41.png)
![us population density map one person equals us population density map one person equals](https://4.bp.blogspot.com/-gTv7AJbVkr8/T3tXb0jrriI/AAAAAAAAADM/IwN_HfD5q94/s1600/2010%2BCensus%2BUnited%2BStates%2BProfile.jpg)
In imaginary ‘Singapore’ example above, we need number that shows livingDensity= 10,000ppl/km2 even when Singapore has 1M people over 10,000km2 ( because all of them live on just 100km2 city area), instead of number that shows classicDensity=100 ppl/km2. That last sentence is key reason for the problem – we need “living” population density that shows average situation in which citizens of that country live, instead of “classical” density which simply shows total population over total country area. This demonstrate that “classic” population density is bad indicator of average population density as seen by average citizen. Classic population density would now show that Singapore has just 100 ppl/km2 density … 100 times lower than before ! And yet, every citizen in Singapore still live in same city as before, under same conditions – which means every citizen still live surrounded by 10,000 people on average on square kilometer. Now imagine that Singapore buys additional 9,900km2 of empty land adjacent to it, so it expand its country area to total 10,000km2, while still only having same 1M people living in original 100km2 city. Imagine that it has 100km2 area, with 1 million population evenly spread across city – classic population density would be 10,000 ppl/km2, and it would really accurately reflect situation in which every citizen of that city-state lives in. To demonstrate, lets imagine country that consists of single city – for example, Singapore. And that is not true in any country, but especially not in countries like Canada ( or Australia, or … ) where most people are concentrated in several big cities, and rest of the land is mostly uninhabited. Main reason is that it shows density that would be realistic only if population is evenly spread across entire country. “Classic” population density obviously is not good indicator for urbanization level. Similar results would be shown for Russia, Australia, Brazil and many other countries – their urbanization levels do not match their classical population density. For example, Canada has classic population density 10 times lower than US, but even cursory internet search will show that Canada has 70%– 80% of people living in urban/metropolitan areas, about same as US ! So while urbanization levels are similar between US and Canada, classic population density of US is an order of magnitude higher than Canada. That map immediately demonstrate that “classic” population density does not relate well to expected “urbanization” levels. To quickly check how well classical population density match urbanization levels of world countries, we can use interactive map below ( which looks similar to map at wikipedia entry about population density ) : “Classical” average population density per world country It is determined by calculating population density of each 30 arc-second cell of the country, assigning each a weight equal to its share of the total country population. Living density of a country – a density metric which measures the density at which the average citizen of a country lives.That allows it to avoid above issues, and can be described as : they rely on ‘census tract’ population data, which is available in US but is not easily available for most of the countries in the worldįor purposes of this analysis I implemented method that is similar to ‘population-weighted density’, but instead of US census tracts data it uses population and area data for each 30 arc-second grid cell in the world ( from NASA SEDAC ).they are focused to densities of urban areas and are thus not suitable to calculate density of entire country.While both methods have advantage over simple population density definition, they also have few shortcomings when we are talking about ‘living population density per world countries’: It is determined by calculating the standard density of each census tract, assigning each a weight equal to its share of the total population, and then adding the segments. Population-weighted density – a density metric which measures the density at which the average person lives.It is determined by ranking the census tracts by population density, and taking the density at which fifty percent of the population lives at a higher density and fifty percent lives at a lower density. Median density – a density metric which measures the density at which the average person lives.On wikipedia there are few approaches mentioned for calculating similar type of density: (*) star next to country name in above table marks group of countries, see below for their definition