> Whereas if you take the extraordinarily difficult step of opening Wikipedia (https://en.wikipedia.org/wiki/Jevons_paradox), you understand the real paradox. Jevons observed that when steam engines get more efficient and individually use less coal, we end up deploying many more steam engines in many new industries and use cases, increasing coal consumption overall.
What difference do you see in this paragraph compared to the one before? Steam engines get more coal-efficient and that means there are more of them burning more coal. This is two observations:
- The cost of steam engines goes down, and the quantity sold goes up.
- The value of coal goes up (it produces more energy per ton), and the quantity sold goes up.
Those results are just as basic as "the cost of coal goes down, and the quantity sold goes up", which is the statement you open by criticizing. I agree there's nothing surprising about it. But there's nothing surprising about the other statements either. The paragraph two statements are both demand increases†, while paragraph 1 is a supply increase, but they all happen on the same X-shaped graph from economics 101. (Or rather, two of them happen on an X-shaped graph measuring supply and demand for coal, and one of them happens on an X-shaped graph measuring supply and demand for engines.)
† "The cost of steam engines goes down" might sound like a supply increase, but the cost that's dropping here is the operating cost and not the manufacturing cost, meaning that, at a given price, more people are willing to buy a steam engine than previously.
> Steam engines get more coal-efficient and that means there are more of them burning more coal.
This misses the key part that actually makes it Jevons Paradox: the reduced cost of operating the machine opened up new industries and applications that massively grew which made overall usage increase.
Something could get more efficient and still have the same number of units in the end. Washing machines have gotten more efficient over time and yet it's not like we have tons more washing machines in the US.
That would require perfectly inelastic demand. It's not a realistic assumption... in any context. Its absence certainly doesn't qualify as a "paradox".
> Washing machines have gotten more efficient over time and yet it's not like we have tons more washing machines in the US.
Do you have any numbers for this?
> Do you have any numbers for this?
Strange you'd really push back on this part. Do you now own multiple washing machines at home because they're more efficient? Seems like a pretty obvious take to me but ok let's go.
Looking at census statistics of durable goods it was in the 80s over 25 years ago.
https://www2.census.gov/programs-surveys/well-being/tables/1...
Nearly 20 years later it was still in the 80s.
https://www.prnewswire.com/news-releases/us-census-bureau-da...
Doesn't seem like there's much room to go up from here unless people are going to start owning multiple for some reason.
Meanwhile they became a lot more energy and water efficient.
> In 2000, 87% of all clothes washers consumed at least 600 kWh/yr. By 2019, 85.4% consumed fewer than 200 kWh/yr.
> The average annual unit energy consumption (UEC) of clothes washers decreased 83.9% between 2000 and 2019
https://oee.nrcan.gc.ca/publications/statistics/aham/2019/wa...
For many things the initial or operating costs aren't what's constraining the market for the product. Clothes washers could be cut in half in cost tomorrow but it's not like I'm now rushing out to go buy twice as many. They could go to only require 5 Whr's to run a load but I'm still going to have about as much laundry. We've pretty much tapped out that market in developed countries, the only really new thing was all in one units becoming more economical to a few percent more of the market that didn't have the plumbing or space availability before.
If we were all too stupid to think of new uses for the steam engine we wouldn't have massively increased their usage by making them cheaper to build and cheaper to operate. We'd have just saved more money and used a bit less coal to do the same things we were doing before. If there isn't a market for the things that steam engine enabled, it doesn't end up becoming Jevons Paradox.
Looking at the Jevons Paradox with spreadsheets and accounting, it wasn't just that the spreadsheet made accounting work so much faster and easier, it's that then the effective output per cost per hour for an accountant dropped massively enabling people to hire part time accountants en masse that increased the demand for accountants. If businesses that never would have bothered for accountants didn't come in and effectively revolutionize what it meant to be an accountant all it would have done was making it cheaper for the same firms to do the same work with fewer people.