Wednesday, August 11, 2021

Trying to Figure Out "Degrowth"

As a long-time fan of Our World in Data and its director Max Roser, I’ve gradually become aware of the bitter feud between Roser and economic anthropologist Jason Hickel. It’s a classic wizard-vs.-prophet duel (in the language of Charles Mann’s wonderful book), between a wizard of global data and a prophet of the degrowth movement.

Hickel has made a regular practice of attacking Roser’s work. Roser in turn has argued for the necessity of further economic growth. The feud has gotten more personal and acrimonious on Twitter, where each accuses the other of misrepresenting his work. From what I’ve seen, some of those accusations are fair—on both sides.

But what fascinates me is not the recurring spat over over who’s misrepresenting whom, but the question of where exactly Hickel and Roser agree and where exactly they differ on the big global issues. I’m still trying to figure this out, but at the risk of getting some nuances wrong, let me try to summarize.

Roser and Hickel both see global poverty as a huge problem. They agree that we must not only eliminate the most extreme poverty (people living on the equivalent of less than $2/day), but strive to raise everyone’s living standards above a much higher threshold.

Hickel and Roser also agree that we need to reduce global carbon emissions very quickly.

But Roser says that the way to do those things is to keep growing the global economy, while Hickel’s slogan is degrowth. How is it that they can agree on the goals while advocating opposite solutions? I’ve been puzzling over this question for quite a while (admittedly without taking the time to read as much of Hickel’s work as I’ve read of Roser’s).

Now Kelsey Piper has published a good article about the degrowth movement on Vox, quoting both Roser and Hickel. And that article gave me an opportunity to ask a version of my question on Twitter:

Much to my delight, this tweet prompted multiple responses from Roser, Hickel, and Piper, adding up to what I thought was a fruitful conversation. Hickel also posted a longer response, summarizing his position.

In his response Hickel says quite plainly that “degrowth is for rich countries.” But which countries does he consider rich? He likes to divide the world into the “global North” and the “global South”, so perhaps he would equate “rich” with the former, which elsewhere he has defined as “US, European Union, Canada, Australia, New Zealand, Russia, Switzerland, Iceland, Israel, Greenland, Norway, Japan”. One obvious problem is that quite a few Asian Tiger and Persian Gulf states are as rich as these. Even Malaysia is as rich as Russia, while Turkey and several Latin American countries are richer than Bulgaria (which I think is the poorest EU country in terms of GDP/capita).

But let’s assume for the sake of consistency that degrowth is for not just the “global North” but also for most of these equally rich countries, down to some cutoff that’s somewhere below Russia. The real problem is that if “degrowth” implies a worldwide GDP/capita goal any significant amount below the level of Russia, we’re leaving little or no room for growth in big middle-income countries like Iran, Mexico, Brazil, and China. Is that really what Hickel wants? Let’s try to dig deeper.

Hickel actually doesn’t like talking about GDP/capita. He instead reframes the discussion in terms of per-capita energy use. This changes a few details, but it doesn’t change the big picture:

Here Iran is above France, Malaysia is above the UK, and China is right behind Italy. Latin America comes out lower in this ranking than by GDP, but in a warm climate you need less fuel for heating.

The general lesson I draw from this data is that it’s really awkward to try to divide the world’s countries into two groups—rich and poor, or North and South. 

The specific lesson for interpreting “degrowth”, I think, is that it’s not fundamentally about the wealth—or the energy usage—of entire countries.

In our recent Twitter thread, when I pressed him on what “degrowth” means for the world as a whole, Hickel replied, “On an aggregate global level, we need a reduction of resource/energy use, and we know this can be done in a way that’s consistent with high levels of well-being for all.” When Piper then pressed him on where he would set that global level, he pointed to a bottom-up model that first estimates the minimum energy needed to give each person “decent material livings” and then assumes that every single person in the entire world will use exactly that amount of energy and no more. Hickel has cited the same study elsewhere, adding a “generous” 75% energy bonus, but he is still envisioning a world in which virtually all inequality is eliminated—not just between countries, but also within countries.

I think it’s important to do this kind of arithmetic, just as a benchmark for comparison. But is there even a shred of empirical evidence that such a radical reduction in inequality is possible? I very much doubt it.

Roser, by contrast, has described a “minimum growth scenario” that’s much closer to empirical reality. Like Hickel, he imagines completely eliminating all inequality between countries. But unlike Hickel, he assumes that inequality within countries would be reduced only to the same level as in present-day Denmark (a country with low inequality by global standards). Then, if every country’s average per-capita income were to match that of Denmark, only 14% of the world’s people (the same percentage as in Denmark today) would fall below Roser’s poverty threshold of $30 income per person per day (and very few people would be far below this).

How much global economic growth would be needed to achieve Roser’s scenario? Assuming that all this could be accomplished by the year 2100, and taking into account the expected world population growth during that time, Roser calculates 410%. That is, the world economy would have to grow to about five times its present size. (Presumably, thanks to “decoupling”, world energy use would grow by a considerably smaller factor.)

So as far as I can tell, the biggest difference between Hickel and Roser is not their vision of future relationships between countries, or whether they think a certain amount of degrowth is reasonable for the very richest countries, or even whether they wish to decrease inequality within most countries. The difference is that Hickel, unlike Roser, is willing to entertain the notion of eliminating virtually all inequality within every country.

People often call Roser an “optimist”, mostly because he draws so much attention to the progress that humanity has made in the past. Fittingly, therefore, he was quick to point out the irony that it’s Hickel, not he, who is making the more wildly optimistic assumptions about the future:

Many thanks to Roser, Hickel, and Piper for this illuminating conversation!

[Updated 17 Aug 2021 to clarify that Roser’s calculation incorporates population growth between now and 2100.]

5 comments:

  1. Have you come across Tim Garrett's economic theory?
    https://link.springer.com/article/10.1007/s10584-009-9717-9
    Treating global society as a heat engine he links our current energy consumption to accumulated wealth, if I understand it correctly. Some interesting conclusions can be drawn. It seems to have worked well over the last 50 years: https://doi.org/10.5194/esd-2021-21
    I'd be interested to hear your thoughts

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  2. Thanks for these links. I've seen Garrett cited before and to be honest I'm not sure what to make of his global modeling work. In general I'm pretty skeptical of trying to apply simple mathematical models to systems that depend on human behavior. I have a piece of writing appearing soon that will express plenty of such skepticism about another author, so watch this space! Meanwhile, what's your opinion of Garrett's model?

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  3. I'm still fairly agnostic about it since I don't feel like I understand it well enough. It seems like wealth can be created by nonphysical processes, like knowledge creation, but of course that has to be supported by physical processes like eating (and is there such thing as a nonphysical process anyway?)so it seems plausible that what we call wealth is basically a unit for available usable energy from the environment..
    I'm also skeptical when people want to treat systems with humans in them differently than ones without ;). Not that you're saying that but as far as depending on human behavior my understanding is that it's not so much dependent on human choices but constraining those choices.

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    1. Yeah, I should have clarified that I'm not suggesting humans are inherently different in this respect from other complicated systems. But human behavior is one of multiple elements that I think can make a system too complicated to understand using the typical physicist's toolkit.

      For a physicist's take on the relationship between physical and economic processes, you might enjoy this blog post by Tom Murphy: https://dothemath.ucsd.edu/2011/07/can-economic-growth-last/

      If you're curious, I agree with Murphy's conclusion that the non-physical economy can't grow to become an arbitrarily large fraction of the total economy. But I disagree with much of the rest of his Malthusian spin.

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    2. Thanks, interesting blog! And very malthusian indeed.

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