How crowded is the World?

By: Lykke E. Andersen* 

“In the last 200 years the population of our planet has grown exponentially,
at a rate of 1.9% per year. If it continued at this rate, with the population
doubling every 40 years,by 2600 we would all be standing literally
shoulder to shoulder.”
Stephen Hawking

To most people, the World feels rather crowded, and many people are worried about the impacts that all we humans have on the environment. In this newsletter, however, I will argue that the perceptions of crowdedness are biased – due to crowding.

Here is a thought experiment: Take the entire World population of 6.67 billion people, group people into families of 5, and give each family a nice house on a generous 600 m² plot. This would require about 800 thousand square kilometers of land, which means that the entire World population would fit comfortably within the borders of Bolivia, even without encroaching on the 17 million hectares of protected areas, and leaving the rest of the planet free of humans.

So the World is not really crowded yet. And the population bomb has by now been defused. Long range population projections made by the UN (1) suggests that the World population probably will reach its maximum around 9 billion this century, and unless fertility trends are reverted, the human population would start shrinking considerably, as almost all developed countries have fertility rates well below replacement level, and fertility rates in developing countries are falling rapidly towards developed country levels (2).

Still, if you live in a big city and rarely get out in the wilderness, which would be the case for most of us, the World does seem crowded.

But we crowd together for very good reasons. Crowding allows us to specialize in what we do best and trade with others, instead of having to make everything we need from scratch in each household. Such specialization creates huge efficiency gains, which is why we have seen such tremendous increases in standards of living during the last few hundred years, during which the worldwide urbanization rate has climbed from just 6% in 1800 to slightly over 50% now. Crowding also promotes technological inventions, like electricity, computers and Internet, which would have been impossible for any of us to invent if we had been living isolated, self-sufficient existences on each of our 10 hectare shares of the World.

Crowding vastly increases our choices, and thus our quality of life. Not only is there an incredible variety of goods, services, jobs and leisure activities to choose from in big cities, but the market for potential partners is also vastly larger than it is for youngsters living in sparsely populated rural areas. Indeed, in rural areas girls often marry when they are very, very young, which makes sense if they (or their parents) are afraid that the only halfway decent bachelor in the area will be snatched up before they turn 18.

For those of us who were not ready to get married and have kids at 13, it is certainly nice to have the choices that cities offer.

*Lykke Andersen is the Director of the Center for Economic and Environmental Modeling and Analysis (CEEMA) at INESAD.

(1) United Nations (2004) “World Population to 2300.”
(2) See, for example, the Gapminder presentation “Has the World Become a Better Place?“