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As far as the example in the article goes I have a question, the 2 additional workers hired by this hypothetical environmentally efficient company use up more energy by commuting only if they were unemployed previously? If they commuted the same distance to their previous job then there is no net increase in energy loss/inefficiency, right? What if these two new employees discover an even greater efficiency? Is this paradox basically saying that any efficiency has to be ubiquitous to really help long term? I think this article needs more info and clarity. zen master T 01:23, 18 Mar 2005 (UTC)
I agree and would like to see the article be much longer. You are correct in your statement that Jevon's paradox implies that the efficiency of overall systems is far more important than individual systems, but it goes one step further. What it is saying is that the economy can now support two new additional workers that could not have been supported before because of the cost savings from using alternative energy. When there is cost savings the economy will expand to consume the conserved resources and the net result will be increased consumption. John187 17:08, 18 Mar 2005 (UTC)
I have doubts about the whole corollary section. First, I cannot see a clear statement of what is the corollary. Second, I think the example is not particularly clear, and a different example might be better. But something about this is still continuing: since 1973, industrialised countries have substantially increased their energy efficiency, and this has helped economic growth, meaning we now consume more energy despite a sharply reduced enegy intensity.
The Corollary is confusing and nonsensical. I'm new to wikipedia so i wont do it, but i'll say that it ruins the article. Also, can't Jevons paradox be applied to labor/wages? (ie as a refutation to marxist "wage slavery"). Marxists believe that increased industrial efficiency would mean perpetually decreasing demand for labor and therefore perpetually decreasing wages- Jevons paradox, if applied to labor, would indicate that as industrial efficiency increases, the demand for labor actually increases because increases in demand for product outstrips increased productivity. I've always that this was a better application of jevons paradox.
I too would like to see an expansion of this article (but also won't be the one to write it) and I'd like to know more about how this can effect overall efficiency efforts. Cars, for instance, appear to be driven more the less is spent on gasoline and hence hybrids may have less efficiency than the raw numbers would suggest. But the amount of use my TV and computer get have almost nothing to do with their power consumption. When does Jevon's paradox apply and when doesn't it? When does greater efficiency result in increased energy usage and when does Jevon's paradox merely result in a drag on efficiency?
Localized solutions to global problems often confound the solution of the overall problem. Jevons paradox implies that as individuals become increasingly efficient, the overall economy will compensate by supporting additional individuals and increasing overall consumption.
For example, consider a green business which attempts to alleviate global environmental concerns by consuming renewable energy resources. If the business saves 10 units of energy from the local power plant which operates at 40% efficiency, they will save 1000 units of currency. This cost savings will allow the business to hire an additional two employees.
However, each of these two employees must commute to work in automobiles. These automobiles still consume 10 units of energy because they operate at only 15% energy efficiency. Thus by switching to renewable energy, the business has reduced the overall energy efficiency per unit of consumed resources from 40% to 15%.
By first saving money, then using it to hire two new employees, the green business has actually expanded the economy. The expansion of the economy will most likely result in an overall increase in energy consumption, which in the example above also shows the possibility of reducing energy efficiency by its effects in the wider community.
This paradox illustrates how difficult it is to solve global economic problems.
Questions:
1) Why does the automobile consumes exactly 10 units of energy, which is exactly the amount saved by the factory?
2) Why does 1 unit of energy cost 100 unit of currency?
3) Why does the efficiency of total energy comsumption drop from 40% to 15% instead of 40% to 35% ? Is the energy efficiency inside the factory drop from 40% to 15% just because two new employees drive to work?
4) Why the assumption that the saving in energy in the factory is less than the energy consumption of two extra automobiles?
"Jevons paradox" is the phrase used in economics. HGB 01:54, 10 August 2005 (UTC)
I've just spent some time googling for the alleged corollary of Jevons paradox and didn't find any mention of it at all. The only hits on Google were Wikipedia and sites that scrape Wikipedia content. If the corollary were part of the normal discussion of Jevons paradox, then it might have a place in the article, but since it doesn't appear to be part of the normal discussion, I'm going to remove it from the article. If someone comes up with some references to the alleged corollary (outside of the Wikipedia article and sites that scraped the article), then we can discuss adding the corollary section back into the article. -- Flatline 00:35, 24 August 2005 (UTC)
Economists have held, since the very beginning, that an increase in supply inceases the quantity supplied and decreases the price. An increase in efficiency means an increase in supply, so of course more will be consumed. This doesn't contradict any intuition and hence is not a paradox. MrVoluntarist 20:43, 4 September 2005 (UTC)
Jevon's Paradox fails when the price of energy is going up since conservation only enables you to keep the bills in place rather than lowering them so you have no additional money from saving energy to spend elsewhere on consuming energy.
It can also fail if all or most of the money from energy savings is invested into more energy efficiency.
Jevons Paradox is well understood in Economics. My edits reflect the mainstream economic view on the subject. Additionally, Energy Policy is a respected peer-reviewed academic journal. As such it represents scholarly consensus on a topic, and should not be treated as if it was one person's view cited off the internet. -- lk ( talk) 18:14, 20 November 2007 (UTC)
Second, it addresses many problems with your version:
OK, let's just assume good faith and restart. I'll be specific about my complaints.
I certainly welcome any edits for readability and logic. However, I would like wikipedia articles to reflect current consensus in the relevant scientific community. Not all views deserve the same weight, see WP:UNDUE. -- lk ( talk) 06:57, 21 November 2007 (UTC)
Thanks for the reference, Lawrencekhoo. I recall you mentioned that the Greening reference showed that the Potter article was out of synch with the mainstream, but having not read it I wasn't comfortable adding it as a reference there myself. (There's some guideline on this, and in general it's intellectually shady to use a reference you haven't read.) Thanks.
CRGreathouse ( t | c) 17:44, 23 November 2007 (UTC)
http://www.sciencedirect.com/science/article/B6V2W-4090S0W-4/2/a9168f95d980746691a756947e935f26
Discussion is over at the Rebound effect (conservation) talk pages. lk ( talk) 08:51, 28 April 2008 (UTC)
I looked at this for about an hour before realizing what it was actually supposed to say. The graphs are not clearly written. It is not clear whether they are referring to the price and quantity of the fuel or of the [i]work which the fuel is used to perform[/i]. This is because both words appear in the graph and the axis are unlabeled. The way the graphs are currently written imply that fuel consumption will increase for any increase in efficiency.
I believe the graphs should be remade with the labels such as "Quantity of work demanded less than doubles". Do you agree? —Preceding unsigned comment added by 71.63.183.199 ( talk) 08:26, 21 May 2009 (UTC)
I've changed the link from efficiency from efficiency (economics) to just plan efficiency, since it's not really economic efficiency we're talking about here, rather the normal sense of being able to get a greater output for a given input. That is, more work for a given amount of fuel. (I wrote the original paragraph, and this is definately the meaning I intended.)
Since this page is also about economics, maybe we need to change the wording a bit so as to avoid any confusion that we could be talking about economic efficiency there?
-- Mathish 10:42, 2 March 2006 (UTC)
I'm new to this so please excuse ant breaches of etiquette. I think it would be best to start again with something like the following:
Jevons Paradox
A proposition put forward by the economist William Stanley Jevons in his book 'The Coal Question' (1865). It asserts that greater efficiency in the use of any resource always increases consumption of it. As a hypothesis it is worthless: it explains nothing which cannot be explained fully by generally accepted economic theory and it cannot be tested because it is impossible to specify a time frame within which the increased consumption must take place.
Scepticc 23:22, 14 January 2007 (UTC)scepticc
How about a reference to prove the economic exceptions in the second paragraph? They smack of speculation and an ideological, not objective, agenda. —Preceding unsigned comment added by JoeBjr ( talk • contribs) 00:07, 3 September 2009 (UTC)
Can we list out the POV problems of the article? In which direction is it slanted? Which sections have problems? LK ( talk) 02:34, 19 September 2009 (UTC)
I need to clarify what exactly this entails. Let's take a simple example of light bulbs. If I get more energy efficient bulbs (though the cost of their production and product lifespan also needs to be taken into account), I use less energy. So it would seem that if everyone installed these new light bulbs, less energy would be consumed. However, because they use less energy, they are also cheaper to use, so people might use lights more than they otherwise would. In this case though, lighting is fairly cheap, so if we use lightbulbs that are twice as efficient we probably won't expect to see twice as much use of light bulbs (maybe a little more, but probably not a big increase). As I understand it, this is the sort of thing that the concept is about. However, would it extend further: we are now spending less on light bulbs, but with the money saved people spend it on something else that consumes energy.
Another conceptually related idea: if I don't use this resource, somebody else will instead (which in reminds me of Hardin's life boat ethics). Do any of these extensions fall under the Jevons paradox blanket? If not, what to call them? Richard001 ( talk) 04:31, 26 April 2008 (UTC)
Richard, you are conflating 2 issues. We should discuss only one at a time. First, the Jevons Paradox, has to do with the rebound effect being larger than 1, so that advances in efficiency lead to more resource use. If this happens, the price at which the resource trades at will go up. Otherwise, more effort will not be put into extracting a resource. Only if improved efficiency causes resource prices to rise, will more be extracted and used. Second, you are also making a type of system wide argument, that somehow in the whole system, everyone together must always use the same amount of resources no matter what happens to technology. There are many problems with such an argument. Suffice to say that in no economics textbook is such a principle mentioned. And so, it would be inappropriate to state as such in a wikipedia article. Full disclosure, I'm an econ prof., so you know where I'm coming from. I'm wary of discussing this further on the talk page. If you really want to pursue this, perhaps we can converse on our respective talk pages. lk ( talk) 06:53, 30 April 2008 (UTC)
Why does 'this' only apply to energy use? US economists are constantly going on about (usually) falling labor productivity and its effect on output. This is not an exact parallel because 'labor' productivity is simply total output divided by labour input, but there seems no reason to say that the principle is not valid for other resources. Jevons specifically argued that his effect applied to the labor of downtrodden and exploited seamstresses, contrary to the general opinion of his time.
Scepticc —Preceding unsigned comment added by Scepticc ( talk • contribs) 08:43, 15 June 2008 (UTC)
lk ( talk) 19:26, 16 June 2008 (UTC)
Regarding your argument that fuel isn't cheese, both Jevons and Brookes argued that the Jevons effect applied to labor. I believe that an encyclopedia article should present the issues to the non-specialist reader. There is a problem with the JP and KBP because there is no substantial literature which comprehensively argues the converse. The UKERC recently published a report which set out to examine the issues but ultimately ducked out of reaching a conclusion. Perhaps in these circumstances one cannot do better here than indicate that the JP is a matter of opinion without good evidence. By the way, I hesitated to edit the reference in the article to James Watt but it is a very condensed (to put it politely) account of Jevons' thinking. 195.92.194.11 ( talk) 08:24, 21 June 2008 (UTC) Scepticc
On further thought I offer the following (cross-references not yet added) as a substitute for the present entry. "Jevons Paradox
The Jevons Paradox (sometimes called the Jevons Effect) is the proposition put forward by W S Jevons in his book "The Coal Question" (1865) that greater efficiency in the use of coal necessarily increases rather decreases its consumption. He attributed this result principally to the increase in demand for products which would result from a fall in their production cost. He offered analogies such as the increase in traffic on toll roads when the tolls were reduced or the increase in yield of an excise duty when its rate was lowered. Nowadays we would apply the concept of the Laffer curve to such situations, recognising that there is some rate of toll or duty which will maximise revenue but that whether revenue rises or falls if the rate is reduced depends on its initial value. Jevons also claimed that seamstresses had not lost income when their efficiency had been raised by the introduction of sewing machines, though the point of relevance to the coal-efficiency question is whether the quantity of labour employed in sewing was increased or decreased. Jevons saw the increased efficiency of steam engines as being likely to extend their fields of application. He also attributed the large increase in Scottish pig-iron output after 1830 to the reduction in coal consumption per ton made possible by the use of the hot blast in smelting.
Jevons was writing at the end of a period of around 30 years during which UK coal consumption had risen faster in percentage terms than it had ever done before or was ever to do again. The editor of the 3rd edition of "The Coal Question" added a footnote which showed that over the period 1869-1903 coal consumption by the UK iron and steel industry fell substantially despite a large increase in output. Thus Jevons was perhaps unduly influenced by the circumstances of his time. He was also writing before Alfred Marshall produced (in the 1890s) the model of supply, demand and prices which forms the basis of today's microeconomics.
The Jevons Paradox continues to find advocates, particularly among environmental economists. A related proposition is the Khazzoom-Brookes postulate, which applies to all energy rather than to coal. Both are implicitly rejected by governments and public agencies around the world that promote energy efficiency as a means of reducing energy consumption and GHG emissions." 195.92.194.11 ( talk) 17:24, 22 June 2008 (UTC) Scepticc
My intention was to replace the whole article. The examples of roads and seamstresses were put forward by Jevons as confirming evidence for his argument. They are fundamental to it and irrelevant to the broader "Coal Question". I don't think Jevons says anywhere that his "paradox" applies to iron. Rather, increased iron production - according to him - increases coal consumption, though he is not very convincing on this. but do you have a reference? Scepticc Scepticc ( talk) 21:55, 3 July 2008 (UTC)
1) The Jevons paradox as discussed by WSJ relates to both coal and labor. But he also assumes that the price elasticity of demand for all sorts of things is > 1 and is happy to argue from that to the much more extreme proposition that reducing the cost of any good or service made using coal will increase demand for that good or service enough to increase the toral consumption of coal. He assumes this despite the fact that it implies a redistribution of consumer expenditure with reduced purchases of other goods and services whose production would also have required energy. Even without Marshall's later insights the JP is therefore a priori dubious. 2)& 4)(I don't understand the difference) If it is only occasionally observed that rebound is greater than 100% then we are ex hypothesi not talking about a general principle worthy of special attention. But I'd be grateful if you could give me some examples - and not the effect of the hot blast on Scottish pig-iron production, which is quite irrelevant, or the cashmere (sometimes ignorantly 'Kashmir') effect. 3) The effect of lower energy prices on growth is likely to be significant but WSJ himself ignored the effect of lower coal prices on demand and in particular the effect of the railways in reducing prices outside the coalfields. But then he didn't have much to say about the effect of the railways on growth anyway. I think there may be a need for a more radical rethink about what should be under "JP" and what under WSJ himself but I'll try to find time to do a proper job soon. scepticc Scepticc ( talk) 11:20, 20 July 2008 (UTC)
![]() | This is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page. |
Archive 1 | Archive 2 | Archive 3 |
As far as the example in the article goes I have a question, the 2 additional workers hired by this hypothetical environmentally efficient company use up more energy by commuting only if they were unemployed previously? If they commuted the same distance to their previous job then there is no net increase in energy loss/inefficiency, right? What if these two new employees discover an even greater efficiency? Is this paradox basically saying that any efficiency has to be ubiquitous to really help long term? I think this article needs more info and clarity. zen master T 01:23, 18 Mar 2005 (UTC)
I agree and would like to see the article be much longer. You are correct in your statement that Jevon's paradox implies that the efficiency of overall systems is far more important than individual systems, but it goes one step further. What it is saying is that the economy can now support two new additional workers that could not have been supported before because of the cost savings from using alternative energy. When there is cost savings the economy will expand to consume the conserved resources and the net result will be increased consumption. John187 17:08, 18 Mar 2005 (UTC)
I have doubts about the whole corollary section. First, I cannot see a clear statement of what is the corollary. Second, I think the example is not particularly clear, and a different example might be better. But something about this is still continuing: since 1973, industrialised countries have substantially increased their energy efficiency, and this has helped economic growth, meaning we now consume more energy despite a sharply reduced enegy intensity.
The Corollary is confusing and nonsensical. I'm new to wikipedia so i wont do it, but i'll say that it ruins the article. Also, can't Jevons paradox be applied to labor/wages? (ie as a refutation to marxist "wage slavery"). Marxists believe that increased industrial efficiency would mean perpetually decreasing demand for labor and therefore perpetually decreasing wages- Jevons paradox, if applied to labor, would indicate that as industrial efficiency increases, the demand for labor actually increases because increases in demand for product outstrips increased productivity. I've always that this was a better application of jevons paradox.
I too would like to see an expansion of this article (but also won't be the one to write it) and I'd like to know more about how this can effect overall efficiency efforts. Cars, for instance, appear to be driven more the less is spent on gasoline and hence hybrids may have less efficiency than the raw numbers would suggest. But the amount of use my TV and computer get have almost nothing to do with their power consumption. When does Jevon's paradox apply and when doesn't it? When does greater efficiency result in increased energy usage and when does Jevon's paradox merely result in a drag on efficiency?
Localized solutions to global problems often confound the solution of the overall problem. Jevons paradox implies that as individuals become increasingly efficient, the overall economy will compensate by supporting additional individuals and increasing overall consumption.
For example, consider a green business which attempts to alleviate global environmental concerns by consuming renewable energy resources. If the business saves 10 units of energy from the local power plant which operates at 40% efficiency, they will save 1000 units of currency. This cost savings will allow the business to hire an additional two employees.
However, each of these two employees must commute to work in automobiles. These automobiles still consume 10 units of energy because they operate at only 15% energy efficiency. Thus by switching to renewable energy, the business has reduced the overall energy efficiency per unit of consumed resources from 40% to 15%.
By first saving money, then using it to hire two new employees, the green business has actually expanded the economy. The expansion of the economy will most likely result in an overall increase in energy consumption, which in the example above also shows the possibility of reducing energy efficiency by its effects in the wider community.
This paradox illustrates how difficult it is to solve global economic problems.
Questions:
1) Why does the automobile consumes exactly 10 units of energy, which is exactly the amount saved by the factory?
2) Why does 1 unit of energy cost 100 unit of currency?
3) Why does the efficiency of total energy comsumption drop from 40% to 15% instead of 40% to 35% ? Is the energy efficiency inside the factory drop from 40% to 15% just because two new employees drive to work?
4) Why the assumption that the saving in energy in the factory is less than the energy consumption of two extra automobiles?
"Jevons paradox" is the phrase used in economics. HGB 01:54, 10 August 2005 (UTC)
I've just spent some time googling for the alleged corollary of Jevons paradox and didn't find any mention of it at all. The only hits on Google were Wikipedia and sites that scrape Wikipedia content. If the corollary were part of the normal discussion of Jevons paradox, then it might have a place in the article, but since it doesn't appear to be part of the normal discussion, I'm going to remove it from the article. If someone comes up with some references to the alleged corollary (outside of the Wikipedia article and sites that scraped the article), then we can discuss adding the corollary section back into the article. -- Flatline 00:35, 24 August 2005 (UTC)
Economists have held, since the very beginning, that an increase in supply inceases the quantity supplied and decreases the price. An increase in efficiency means an increase in supply, so of course more will be consumed. This doesn't contradict any intuition and hence is not a paradox. MrVoluntarist 20:43, 4 September 2005 (UTC)
Jevon's Paradox fails when the price of energy is going up since conservation only enables you to keep the bills in place rather than lowering them so you have no additional money from saving energy to spend elsewhere on consuming energy.
It can also fail if all or most of the money from energy savings is invested into more energy efficiency.
Jevons Paradox is well understood in Economics. My edits reflect the mainstream economic view on the subject. Additionally, Energy Policy is a respected peer-reviewed academic journal. As such it represents scholarly consensus on a topic, and should not be treated as if it was one person's view cited off the internet. -- lk ( talk) 18:14, 20 November 2007 (UTC)
Second, it addresses many problems with your version:
OK, let's just assume good faith and restart. I'll be specific about my complaints.
I certainly welcome any edits for readability and logic. However, I would like wikipedia articles to reflect current consensus in the relevant scientific community. Not all views deserve the same weight, see WP:UNDUE. -- lk ( talk) 06:57, 21 November 2007 (UTC)
Thanks for the reference, Lawrencekhoo. I recall you mentioned that the Greening reference showed that the Potter article was out of synch with the mainstream, but having not read it I wasn't comfortable adding it as a reference there myself. (There's some guideline on this, and in general it's intellectually shady to use a reference you haven't read.) Thanks.
CRGreathouse ( t | c) 17:44, 23 November 2007 (UTC)
http://www.sciencedirect.com/science/article/B6V2W-4090S0W-4/2/a9168f95d980746691a756947e935f26
Discussion is over at the Rebound effect (conservation) talk pages. lk ( talk) 08:51, 28 April 2008 (UTC)
I looked at this for about an hour before realizing what it was actually supposed to say. The graphs are not clearly written. It is not clear whether they are referring to the price and quantity of the fuel or of the [i]work which the fuel is used to perform[/i]. This is because both words appear in the graph and the axis are unlabeled. The way the graphs are currently written imply that fuel consumption will increase for any increase in efficiency.
I believe the graphs should be remade with the labels such as "Quantity of work demanded less than doubles". Do you agree? —Preceding unsigned comment added by 71.63.183.199 ( talk) 08:26, 21 May 2009 (UTC)
I've changed the link from efficiency from efficiency (economics) to just plan efficiency, since it's not really economic efficiency we're talking about here, rather the normal sense of being able to get a greater output for a given input. That is, more work for a given amount of fuel. (I wrote the original paragraph, and this is definately the meaning I intended.)
Since this page is also about economics, maybe we need to change the wording a bit so as to avoid any confusion that we could be talking about economic efficiency there?
-- Mathish 10:42, 2 March 2006 (UTC)
I'm new to this so please excuse ant breaches of etiquette. I think it would be best to start again with something like the following:
Jevons Paradox
A proposition put forward by the economist William Stanley Jevons in his book 'The Coal Question' (1865). It asserts that greater efficiency in the use of any resource always increases consumption of it. As a hypothesis it is worthless: it explains nothing which cannot be explained fully by generally accepted economic theory and it cannot be tested because it is impossible to specify a time frame within which the increased consumption must take place.
Scepticc 23:22, 14 January 2007 (UTC)scepticc
How about a reference to prove the economic exceptions in the second paragraph? They smack of speculation and an ideological, not objective, agenda. —Preceding unsigned comment added by JoeBjr ( talk • contribs) 00:07, 3 September 2009 (UTC)
Can we list out the POV problems of the article? In which direction is it slanted? Which sections have problems? LK ( talk) 02:34, 19 September 2009 (UTC)
I need to clarify what exactly this entails. Let's take a simple example of light bulbs. If I get more energy efficient bulbs (though the cost of their production and product lifespan also needs to be taken into account), I use less energy. So it would seem that if everyone installed these new light bulbs, less energy would be consumed. However, because they use less energy, they are also cheaper to use, so people might use lights more than they otherwise would. In this case though, lighting is fairly cheap, so if we use lightbulbs that are twice as efficient we probably won't expect to see twice as much use of light bulbs (maybe a little more, but probably not a big increase). As I understand it, this is the sort of thing that the concept is about. However, would it extend further: we are now spending less on light bulbs, but with the money saved people spend it on something else that consumes energy.
Another conceptually related idea: if I don't use this resource, somebody else will instead (which in reminds me of Hardin's life boat ethics). Do any of these extensions fall under the Jevons paradox blanket? If not, what to call them? Richard001 ( talk) 04:31, 26 April 2008 (UTC)
Richard, you are conflating 2 issues. We should discuss only one at a time. First, the Jevons Paradox, has to do with the rebound effect being larger than 1, so that advances in efficiency lead to more resource use. If this happens, the price at which the resource trades at will go up. Otherwise, more effort will not be put into extracting a resource. Only if improved efficiency causes resource prices to rise, will more be extracted and used. Second, you are also making a type of system wide argument, that somehow in the whole system, everyone together must always use the same amount of resources no matter what happens to technology. There are many problems with such an argument. Suffice to say that in no economics textbook is such a principle mentioned. And so, it would be inappropriate to state as such in a wikipedia article. Full disclosure, I'm an econ prof., so you know where I'm coming from. I'm wary of discussing this further on the talk page. If you really want to pursue this, perhaps we can converse on our respective talk pages. lk ( talk) 06:53, 30 April 2008 (UTC)
Why does 'this' only apply to energy use? US economists are constantly going on about (usually) falling labor productivity and its effect on output. This is not an exact parallel because 'labor' productivity is simply total output divided by labour input, but there seems no reason to say that the principle is not valid for other resources. Jevons specifically argued that his effect applied to the labor of downtrodden and exploited seamstresses, contrary to the general opinion of his time.
Scepticc —Preceding unsigned comment added by Scepticc ( talk • contribs) 08:43, 15 June 2008 (UTC)
lk ( talk) 19:26, 16 June 2008 (UTC)
Regarding your argument that fuel isn't cheese, both Jevons and Brookes argued that the Jevons effect applied to labor. I believe that an encyclopedia article should present the issues to the non-specialist reader. There is a problem with the JP and KBP because there is no substantial literature which comprehensively argues the converse. The UKERC recently published a report which set out to examine the issues but ultimately ducked out of reaching a conclusion. Perhaps in these circumstances one cannot do better here than indicate that the JP is a matter of opinion without good evidence. By the way, I hesitated to edit the reference in the article to James Watt but it is a very condensed (to put it politely) account of Jevons' thinking. 195.92.194.11 ( talk) 08:24, 21 June 2008 (UTC) Scepticc
On further thought I offer the following (cross-references not yet added) as a substitute for the present entry. "Jevons Paradox
The Jevons Paradox (sometimes called the Jevons Effect) is the proposition put forward by W S Jevons in his book "The Coal Question" (1865) that greater efficiency in the use of coal necessarily increases rather decreases its consumption. He attributed this result principally to the increase in demand for products which would result from a fall in their production cost. He offered analogies such as the increase in traffic on toll roads when the tolls were reduced or the increase in yield of an excise duty when its rate was lowered. Nowadays we would apply the concept of the Laffer curve to such situations, recognising that there is some rate of toll or duty which will maximise revenue but that whether revenue rises or falls if the rate is reduced depends on its initial value. Jevons also claimed that seamstresses had not lost income when their efficiency had been raised by the introduction of sewing machines, though the point of relevance to the coal-efficiency question is whether the quantity of labour employed in sewing was increased or decreased. Jevons saw the increased efficiency of steam engines as being likely to extend their fields of application. He also attributed the large increase in Scottish pig-iron output after 1830 to the reduction in coal consumption per ton made possible by the use of the hot blast in smelting.
Jevons was writing at the end of a period of around 30 years during which UK coal consumption had risen faster in percentage terms than it had ever done before or was ever to do again. The editor of the 3rd edition of "The Coal Question" added a footnote which showed that over the period 1869-1903 coal consumption by the UK iron and steel industry fell substantially despite a large increase in output. Thus Jevons was perhaps unduly influenced by the circumstances of his time. He was also writing before Alfred Marshall produced (in the 1890s) the model of supply, demand and prices which forms the basis of today's microeconomics.
The Jevons Paradox continues to find advocates, particularly among environmental economists. A related proposition is the Khazzoom-Brookes postulate, which applies to all energy rather than to coal. Both are implicitly rejected by governments and public agencies around the world that promote energy efficiency as a means of reducing energy consumption and GHG emissions." 195.92.194.11 ( talk) 17:24, 22 June 2008 (UTC) Scepticc
My intention was to replace the whole article. The examples of roads and seamstresses were put forward by Jevons as confirming evidence for his argument. They are fundamental to it and irrelevant to the broader "Coal Question". I don't think Jevons says anywhere that his "paradox" applies to iron. Rather, increased iron production - according to him - increases coal consumption, though he is not very convincing on this. but do you have a reference? Scepticc Scepticc ( talk) 21:55, 3 July 2008 (UTC)
1) The Jevons paradox as discussed by WSJ relates to both coal and labor. But he also assumes that the price elasticity of demand for all sorts of things is > 1 and is happy to argue from that to the much more extreme proposition that reducing the cost of any good or service made using coal will increase demand for that good or service enough to increase the toral consumption of coal. He assumes this despite the fact that it implies a redistribution of consumer expenditure with reduced purchases of other goods and services whose production would also have required energy. Even without Marshall's later insights the JP is therefore a priori dubious. 2)& 4)(I don't understand the difference) If it is only occasionally observed that rebound is greater than 100% then we are ex hypothesi not talking about a general principle worthy of special attention. But I'd be grateful if you could give me some examples - and not the effect of the hot blast on Scottish pig-iron production, which is quite irrelevant, or the cashmere (sometimes ignorantly 'Kashmir') effect. 3) The effect of lower energy prices on growth is likely to be significant but WSJ himself ignored the effect of lower coal prices on demand and in particular the effect of the railways in reducing prices outside the coalfields. But then he didn't have much to say about the effect of the railways on growth anyway. I think there may be a need for a more radical rethink about what should be under "JP" and what under WSJ himself but I'll try to find time to do a proper job soon. scepticc Scepticc ( talk) 11:20, 20 July 2008 (UTC)