The World’s Greatest Graph

A picture worth 2,000 years

As data science seeps into everything, data visualizations are becoming the coin of our realm. Everywhere, people speak in charts and graphs, illustrating data or failing in the attempt. Looking at presentations from decades gone by, in Mad Men, for instance, it’s hard to believe that, once upon a time, people and businesses could make so many decisions without a series of charts to back them up.

Not all visualizations are equal, however. Some are ugly, others are confusing, and many are just plain misleading. Mostly, though, they are just boring. The most beautiful, clearly labeled, accurately represented visualizations are nothing if they don’t tell us something new - the statistical version of “all hat and no cattle.”

Others are brilliant, conveying complex insights and long stories into a single visual. I will spare you a tour of my favorites and jump straight to the best: world GDP over time. As elegant as Chanel’s little black dress, it has only one dataset, uses a linear scale, and has only one color pattern. But, through the use of a single line, it tells us the entire journey of the world.

Global GDP, courteousy of Our World in Data

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Some limitations

Before we get carried away, however, we should acknowledge that the graph isn’t perfect. There are several things we might quibble with. Among the ones that bother me most:

1. Our World in Data chose to use a complicated measure of “International Dollars.” While the idea of using purchasing power parity makes sense, we would need to read the whole article to understand exactly how they did this, which is annoying.

2. The data going back 2,000 years is not great, so a lot of assumptions have been made to get the initial numbers. The Maddison database is tremendous, but it’s not perfect.

3. Third, it’s unclear exactly why they chose the years they did (e.g., skipping 2000 in favor of 2022), why the vertical axis stops at $120T while the dataset keeps going up, or why the data points and the line are the same color. But these are minor aesthetic choices, for the most part.

Why it’s great 

So, why is this graph amazing? It tells us the story of the world in a single visual. And not just that: it tells a beautiful, joyful story that provides some much-needed balance to the anxiety around us from all the elections happening around the globe right now. Let us walk through the things we learn in this story.

First, the world has been in dire straights only until recently. The world GDP line is basically zero for the first 1,500 years. That’s not bad, that’s catastrophic. Sometimes, we kid ourselves that the world was better in ‘ye olden days,’ thinking that agrarian humans lived like hobbits in the Shire, eating organic food, frolicking in the grass, and enjoying deep, close-knit communities. The opening dance for the 2012 Olympics in London, for example, told a beautiful yet misinformed story of English history in which people lived as peaceful agrarians until the smokestacks of the Industrial Revolution killed them off, only to be saved by the NHS. In fact, academic work shows that farmers before the industrial revolution, British farmers could expect a famine every 9-13 years.¹ The famines would crush not only families, given that farmers’ experiences are highly correlated with geography. Consequently, whole communities regularly starved. Going back further is worse: violence has long been a leading cause of death for men in nomadic communities.² Hobbes’s description of life as “nasty, brutish, and short” is not without reason.

Second, the graph tells us that, economically speaking, there has never been a better time to be alive. The most recent data point is the highest one; we live in the most prosperous time the world has ever known. Though we may sympathize with Taylor Swift’s sentiments that it would be fun to live in 1830 “but without all the racists,” in fact, we would only wish that if we could be royalty there, and even then, we would be taking a big loss economically. 

Third, the monotonically increasing nature of the graph gives us some sense of direction. The derivative is positive, and so is the second derivative - economic growth is increasing at an increasing rate. While looking at the OECD’s tepid growth numbers - 2.7% in 2023 - can make this seem implausible.³ In fact, the developing world is growing rapidly. China and India deserve significant credit here: by lifting hundreds of millions out of poverty, they have made the world better than ever. 

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Lest we get carried away

While all this is great, we don’t want to get carried away. While generally a reserved group, economic historians can sometimes get giddy about this graph and start inferring too much from it. Let me highlight a couple of the more common mistakes.

First, this only represents economic growth. GDP is great but it has its limits. It does not tell us about climate, health, meaning, community, freedom, security, etc. While there is significant debate about how useful GDP is, and what we might want to replace it with, it is clear that GDP is not a magic number that tells us all about everything. 

Laurence J. Peter’s famous statement, “Statistics are like bikinis; what they reveal is suggestive, but what they conceal is vital,” is apt here. A graph (or metric) that attempts to measure everything would be illegible and uninterpretable. So, by only reporting GDP, the graph tells us a clear and compelling history of the world, but we should not be so simple as to believe it tells us everything about the world.

Second, this is not to say we live in the best of all possible worlds. This is a mistake more often made by economists, and especially those with ties to Silicon Valley. Yes, this is the best time to be alive, but that does not mean we could not have made better choices or be making better ones now. While this graph gives us reason to be joyful and optimistic, it does not justify being a Pollyana. Economists, like Candid’s Pangloss, can be far too quick to overlook catastrophes by pointing to economic growth. Though the growth on this graph is amazing, it could be more amazing yet!

The third mistake is a bit more nuanced. As noted above, the graph does suggest further growth - our “prior” should be that growth will continue. But people commonly mistake this to mean that progress is inevitable, and that is extrapolating too far. As the investment management industry often reminds us, past performance does not guarantee future performance. A quick look at the historical record reveals that things can and do sometimes get worse. Many (perhaps even most) countries have gone through significant ups and downs economically and, by extension, in their standard of living. Consider the fall of Rome, the humiliation of China, and the collapse of Ancient Greece, to name a few. Even the world as a whole can undergo significant fluctuations. For instance, after the fall of Rome, the world, on average, experienced a setback, leading to ages that were (don’t say “dark”) distinctly less good (though basically still near zero).

Fourth, and finally, your mileage may vary. It’s true that the world is better off, but the experiences of countries, regions, and individuals will differ greatly. Personal preference also plays a key role. People want odd things; I’m sad to tell you that there are some who would exchange a toilet for their phone, just as there are some who really do want to live in ancient Rome despite the lack of penicillin.⁴ While this graph tells us about the world, it does not necessarily tell us about our own story. It’s suggestive but not conclusive.

Conclusion

Exciting listeners' imaginations is critical to good storytelling. And what I love most about this graph is the thoughts it elicits, even if only from me. The simple, stark message of this visualization encourages viewers to ask themselves why the line is the way it is and what it means. As someone who presents graphs to people for a living, that is the holy grail. By telling us a very clear story, it excites us to probe further. That is all we can ask. 

1. McCloskey, Donald N. "The Open Fields of England: Rent, Risk, and the Rate of Interest, 1300-1815." Markets in History: Economic Studies of the Past (1989): 5-51.

2. Roser, Max. “Data Review: Ethnographic and Archaeological Evidence on Violent Deaths.” Our World in Data, December 28, 2023. https://ourworldindata.org/ethnographic-and-archaeological-evidence-on-violent-deaths.

3. Outlook, OECD Economic. "Prospects for Growth and Imbalances beyond the Short Term." OECD Economic Outlook 2023, no. 1 (2023): 1, accessed at: https://www.oecd-ilibrary.org/sites/ce188438-en/index.html?itemId=/content/publication/ce188438-en

4. Gordon, Robert. The Rise and Fall of American Growth: The US Standard of Living Since the Civil War. Princeton University Press, 2017.