During the 1990s, estimating the length of its coastline, Norway’s mapping agency said 57,000 km.
Now they say a whopping 104,600 km.
It’s tough to measure a coastline. Because they are curved, squiggly, and differ seasonally, their lengths change. In fact, it could be impossible.
According to mathematician Lewis Fry Richardson, the smaller the measurement, the longer an imperfect line. As a result, with the tiniest ruler, the line could be infinite. From there, we can leap to our many allusions (including here and here) to the British coastline. So many times during the past decade, we’ve referred to fractal mathematician Benoit Mandelbrot’s comment that the closer you look, the more you see.
And now again, we have it with Norway. As technology permitted mappers to digitize their numbers, Norway’s coastline increased from 57,000 km during the 1990s to 101,000 km in 2011 and to 104,600 km in 2023. And from here, we can ask about the shifting length elsewhere. Currently, Norway’s coastline is the second longest in the world. As #1, Canada’s lead could shrink or increase. In addition, sort of like a watery horserace, Greenland could sneak into first place.
These three images from The Economist display an increasingly longer British coastline:
At this point, you might wonder (as did I) why coastline length matters. Most obviously, we can say that nations need to know their borders and the land, labor, and capital over which they have jurisdiction. An Economist journalist also reminds us that Google has depicted different borders, depending on its audience. Her examples included Crimea where, in 2014, Google displayed it as a part of Ukraine to Ukraine browsers and as Russia to those in Russia. Meanwhile, for the rest of us, it had a dashed line. She also noted that the Spratly Islands are entirely or partially claimed by China, Taiwan, Malaysia, the Philippines, and Vietnam.
In “The Economics of Maps,” researchers again remind us that maps have economic and social consequences. They tell us that mapping decisions can reflect cost, mapmaking technology, and the goals and incentives of the mapmakers. More precisely, coastline mapping has illustrated flooding with inaccurate information. As a result, risk was mispriced and misjudged.
Our Bottom Line: Thinking At The Margin
Economists like to say that we think at the margin. The margin is that imaginary line where we can add some sleep or drive faster or study longer or eat more. Choosing a budget, Congress is always at the margin when it allocates extra dollars to different agencies.
Similarly, the tale of Norway’s coastline is a story about climbing margins. But most crucially, it displays the vagaries of statistics., Whether we are looking at the GDP or a coastline, where you look depends on what we see. And then it can determine what you do.
My sources and more: In a section from news editor Caroline Carter, my Economist newsletter for June 27 looked at Norway’s coastline. (I could find no link for you to see.) But then, for the academic perspective, this paper came in handy.