Who will win the Simon-Ehrlich bet in different decades, and what do long-term prices tell us about resource scarcity?

In 1980, biologist Paul Ehrlich agreed to a bet with economist Julian Simon on how the prices of five materials would change in the next decade.

Paul Ehrlich has clear expectations. He thought that population growth would quickly deplete the planet’s resources.¹ As a result, he expects the cost of resources – including minerals – to rise dramatically as they become more scarce.²

This claim caught the attention of Julian Simon, who expected the opposite. Simon thinks that human innovation and creativity can overcome the scarcity of resources, and the price of resources, therefore, will not rise but fall. In the pages of Social Science Quarterlyhe challenged Ehrlich to put the money on the line.

Simon offered Ehrlich the chance to pick any resource he wanted for the bet. Ehrlich chose five: chromium, copper, nickel, tin, and tungsten. The two bet $1,000 — $200 on each metal — whether the inflation-adjusted prices of these resources in September 1990 would be higher or lower than in September 1980.³ If the price goes up, Ehrlich wins. If they had fallen, Simon would have won.

The chart below shows us the change in the price of five materials in 1990 compared to 1980. Note that it is based on the average prices of that year, not necessarily the price in September of each year. But the final results of the bet are the same, even if you take annual average prices or in particular in September.

All five became cheaper, so Simon won the bet (and Ehrlich mailed him the check).

The cost of tungsten and tin is more than 60% lower. Copper is about 20% cheaper. Nickel and chromium are just cheaper than they were a decade ago. None of them went up in price, contrary to Ehrlich’s prediction.

Click to open the interactive version

There is much debate as to whether Simon “got lucky” with this bet.⁴

The chart above shows that he was relatively lucky with nickel and chromium. If the bet ended in 1989 rather than 1990, the price of these two materials would be higher.

But a more general way to analyze this bet is to ask who would have won if it had happened in any other decade of the 20th and early 21st century.

I looked at inflation-adjusted price data — from United States Geological Survey – for these five materials since 1900. Then I calculated who would have won each decade if they had bet on each of the five metals separately.

If the average annual price of end in a given decade (eg, 1930) is lower than at the beginning (eg, 1920), then Simon wins that decade. If the price is higher, Ehrlich does.

See the chart to see the result. The price of all five elements varies over time. Look at chromium at the top, for example. In a few decades, the price fell. In others, it went up. Whenever the price was higher at the end of the decade than at the beginning, Ehrlich would have won – those parts of the line I’ve colored in red. Simon would have won when the price fell between the beginning and the end of a decade — the line segments are colored blue.

It’s a pretty even split. Simon and Ehrlich both should have won by halftime. But as I will explain, I think the long-term data tell us a slightly different story: one that is more consistent with Simon’s worldview than Ehrlich’s.

This bet has come to represent a clash of worldviews: are we exhausting the planet of its resources, or will humans effectively respond to scarcity to ensure we don’t run out?

Understanding which of these world models is more “correct” is very important for my work going forward. This inspired me to dig into the Simon-Ehrlich wager data in more detail.

But the more I thought about it, the more the original bet missed Simon and Ehrlich’s divergent worldviews.

Looking at mineral prices for just ten years doesn’t reflect the outlook of the two.

Ehrlich’s core argument is that human needs exceed the available resources of the planet.⁶ His argument is that prices will rise dramatically over time as resources become scarcer.

Simon’s view is that this should not happen. As resources become scarcer – and prices rise to reflect it – human change and supply changes must respond and drive prices down.

In other words, both worldviews are about changes eventually.

Simon, in particular, is very specific about this in his initial claim for the bet: “to bet US$10,000… I believe that the cost of non-government controlled raw materials (including grain and oil) will not rise in the long run”. The emphasis is on “eventually”.

The problem is that Simon and Ehrlich agreed on a bet about short changes.

Their ten-year bets are susceptible to short-term fluctuations, often unrelated to actual changes in physical supply and demand. Instead, they are influenced by geopolitical or temporary economic forces. That means it can win depending on random changes every year without reflecting their worldview.

A more meaningful test for their arguments is the change in prices in the long run, which is a signal in fashion than cassava.

With all that in mind, here’s why the long-term data makes me side more with Simon’s view than Ehrlich’s.

Let’s look again at the century-long price trends of five materials. They are shown in the chart below.

The key takeaway for me is that, over time, prices haven’t changed much. Much has changed since 1900, but the prices of the five metals, surprisingly, are not much different from what they were in 1900. Chromium, perhaps, is the one exception where the average prices of the last few decades higher than before. in the early 20th century (although prices in 2020 are the same as in 1900).

In general, material values ​​fluctuate up and down but around a reasonably constant level. The time series is noisy, but the signal so prices haven’t changed much in more than a century.

Studies dating back to 1840 have found that mineral prices – more than five below – are “untrendy” in the long term.⁷

Click to open the interactive version

Importantly, this is despite the fact that the world produces many more of these materials. The chart below shows the change in global production of each of the five materials since 1900.

Today, the world produces 40 times more copper per year and 250 times more nickel than in 1900.

The fact that we are producing more materials than ever, even though the prices are almost unchanged, suggests that contrary to Ehrlich’s prediction, we are not about to run out of these materials anytime soon. That’s what brought me closer to Simon’s worldview.

Click to open the interactive version

Hannah Ritchie (2025) - “Who would have won the Simon-Ehrlich bet over different decades, and what do long-term prices tell us about resource scarcity?” Published online at OurWorldinData.org. Retrieved from: 'https://ourworldindata.org/simon-ehrlich-bet' (Online Resource)

@article{owid-simon-ehrlich-bet,
    author = {Hannah Ritchie},
    title = {Who would have won the Simon-Ehrlich bet over different decades, and what do long-term prices tell us about resource scarcity?},
    journal = {Our World in Data},
    year = {2025},
    note = {https://ourworldindata.org/simon-ehrlich-bet}
}

Reuse this work freely

All visualizations, data, and code produced by Our World in Data are fully open access under the Creative Commons BY license. You have permission to use, distribute, and reproduce it in any medium, as long as the source and the authors are credited.

Data created by third parties and made available in Our Data World is subject to license terms from the original third party authors. We always identify the original source of data in our documentation, so you should always check the license of any such third party data before use and distribution.

All in our charts can be embedded on any site.