Talk:I = PAT

Untitled - Neutrality

Perhaps these variables can be quantified, but it is arbitrary to conclude that there is a directly proportional relationship here. This "formula" is an abstraction of the relationship between these factors, and should be treated as such, rather than as a literal mathematical equation. — Preceding unsigned comment added by 66.31.30.190 (talk) 01:34, 28 November 2011 (UTC)

Regarding the prior comment (from IP 66.31.30.190), all scientific equations that describe natural phenomena are an "abstraction of the relationship between" those phenomena. Furthermore, it is difficult to see how you can question the proportionality of the terms in the I=PAT formula. If we objectively quantify a population and that population's average consumption of a particular commodity, then multiply that by the measured average impact of one unit of that commodity (expressed in terms of pollution levels, habitat destruction, or any other objective measure of environmental damage) then the equation is by definition determinative of the total impact caused by the population. For example, if I know there are 300 million Americans, I know they consume on average 13 megawatt-hours of electricity each year, and I know that U.S. power plants emit about 0.6 tons of CO2 per megawatt-hour consumed, then I can (very non-arbitrarily) deduce that the total impact in terms of CO2 emissions from U.S. electricity consumption is on the order of 2.3 billion tons of CO2 per year.

Depending on what kinds of impacts are being quantified there may be more or less uncertainty associated with the measurement of the variables in the I=PAT equation. Average impact per unit of consumption (T) can be difficult in some circumstances to measure. There may also be uncertainty associated with measuring consumption (A), depending on the goods, services, or commodities in question. And there are always uncertainties in measuring large populations (such as global population). But just because measurement of these quantities is uncertain does not mean that their relationship is not directly proportional.

These issues are, I believe, at the heart of Beremiz's concerns as well. The formula itself may be general, but as long as the units for the variables are clearly and objectively defined, there is nothing remotely subjective or arbitrary about it. Moreover, the apparent uneasiness of the commenters here does not appear to be related to the neutrality of the article, which according to the flag is being disputed. If there is an assertion of bias, then it needs to be much more strongly and clearly asserted! Where, exactly, does the article present a biased point of view in describing the origin of the equation and how it is used?

If there are specific concerns about subjectivity in the way the formula has been applied in practice (e.g., you've seen an example where someone tried to evaluate the human impact on the happiness of turtles, or you are concerned in general about how people define the notion of "environmental impact"), then by all means identify these concerns and add to the article a discussion of them and how the formula could be applied or misapplied. In the meantime, I move that the disputation of the article's neutrality be removed, since right now it provides a simple, objective description of both the formula's origin and how its terms are generally defined. Hookbrah (talk) 22:56, 12 January 2012 (UTC)

Untitled

It looks like the following phrase in the article is misspelled:

"by changed is production"

Fixed, thanks for pointing that out :-) --Commander Keane 02:37, 27 March 2007 (UTC)

I PAT ... formula?!

It does not make any sense, absolutely, to attribute mathematical characteristics to anything that is not "mathematicizable" [1] in essence. In fact, neither human nor environmental questions seem to be able to a mathematical approach, as ordinarily stated. This is only a great mistake, and shows deep ignorance about this theme. Saying that environmental impact depends upon that three factors (variables? — as it has been said in mathematical terms) — and more: in a crescent mode — is a well defined (and comprehensible) assertive. An entirely different thing is to postulate an equation (better, identity) which states a multiplicative concatenation between them! Despite seeming scientifically embased, this statement affronts human intelligence, although it is true that [the idea expressed by] "the equation can aid in understanding some of the factors affecting human impacts on the environment".Beremiz^Cpa? 11:21, 12 October 2010 (UTC)

Unclear what your point is or how you are suggesting to improve the article.

The topic is certainly mathematicizable. Some of the factors can be measured quite easily, at least in theory, (e.g. Population), the other factors are more difficult to quantify, but are certainly quantifiable, and there have been many measures made of them.

Simple dimensional analysis shows that the formula makes sense. Zodon (talk) 22:53, 12 October 2010 (UTC)

Absolutely, not. It seems that you did not understand the inherent reflexion. Although is desirable to furnish such an expression (scientists seem to be glad with that, and, so, repassing this feeling to people...), however, in essence it is only a forced relationship, dressed with mathematical dresses. Dimensional analysis, if needed, may attend all you want... Beremiz^Cpa? 12:59, 16 October 2010 (UTC)

So what are you suggesting - that multiplying per capita consumption by the population doesn't yield total consumption (e.g.)? How are you proposing to improve the article? Zodon (talk) 06:29, 17 October 2010 (UTC)

Note I have said above "[...] it is true that [the idea expressed by] "the equation can aid in understanding some of the factors affecting human impacts on the environment"". Hence, it must be understood at all that I am not advocating against the usefulness of the conceptual idea itself, as expressed (in forced terms, really) by the so called "I PAT formula". What I want just to point out is this: (1) population (P) is passible of mathematical measurement; (2) affluence (A: consumption per capita) maybe reasonably passible of mathematical measurement; but... (3) technology (T: environmental impact per unit of consumption), as so poorly expressed, certainly is not passible of mathematical measurement! So, the regarded "I quantity", expressed as a function of that other three, will not get that goal too. It must be point here that I am not contending the abstract idea contained in that "formula". What I am criticizing (under so clear arguments) is the absolute carence of logical-mathematical meaning in a expression present without any more attention to the rigour that must be turned on in such cases. Beremiz^Cpa? 04:50, 18 October 2010 (UTC)

[Outdent] The quantifiability of T, and of I can be verified - just consider all the articles that deal with these topics. I: (Sustainability measurement, various footprints - carbon, water, ecological) T: (Embodied energy, Life cycle assessment, plus the environmental impact of gathering the related components) Per your suggestion I have added some clarifying links for T, hope that helps. Zodon (talk) 05:55, 18 October 2010 (UTC)

• Thanks for now! But, I still remain being so wary about such an approach, when dealing with such questions. It is often reported that Lord Kelvin said "If you can measure that of which you speak and can express it by a number, you know something of your subject; but if you cannot measure it, your knowledge is meager and unsatisfactory." On the other hand, it is also often reported that Albert Einstein said "Not everything that counts can be counted, and not everything that can be counted counts." Contradiction? Paradox?!... I think no. In any manner — regarded to Lord Kelvin's words, but remembering Albert Einstein's words too... — it does not be forgotten that there are many other means of "to measure, lato sensu, something", wich not require quantification by numbers... Nothing, absolutely, nothing against numbers; everything in favour them. But, I do really think that, despite some anxiety for attributing numerical values to everything, there are "conceptual means for evaluation", better and better than any other, when dealing with some specific human related questions. I PAT relationship pointed as a formula is such an example. Thanks. Beremiz^Cpa? 16:04, 18 October 2010 (UTC)

---

Of course T is ill defined and amorphorous. So isn't the concept of I, environmental impact. Both I and T define dimensional analysis. Nevertheless, IPAT is extremely useful in framing the magnitudes of effects. If P doubles and A doubles, then T must reduce to 0.25 of former value just to maintain status quo. That is an understandable concept.

Too many people believe that if they buy compact light bulbs, drive a Prius and buy alternative energy, that the world will be restored to pre-hockey stick curve splendor. Those changes are not nearly enough. People need to grasp the magnitude of change as well as the direction of change. To that point, IPAT can help.User:Anorlunda 17:54, 29, January 2012 (UTC)

Dr. Liddle's comment on this article

Dr. Liddle has reviewed this Wikipedia page, and provided us with the following comments to improve its quality:

I think one statement is too strong and I have a suggestion to expand the article:

I disagree with the following statement:

Similarly, an extensive historical analysis of technological efficiency improvements has conclusively shown that energy and materials use efficiency improvements were almost always outpaced by economic growth, resulting in a net increase in resource use and associated pollution.[11][12]

Efficiency improvements in OECD countries have made significant macro-differences in energy/emissions. For example, since the 1970s value added in manufacturing has outpaced energy consumption in that sector for OECD countries as a whole. Indeed, industry energy intensity fell by about 40% from 1970-2005 (there is a rather extensive literature looking into the sources of this energy intensity decline). Also, in the US over the period 1978-1990 (a time in which the CAFE standards were increasing annually), vehicle miles traveled increased twice as fast as motor fuel use—whereas, before and after that period, those two variables grew nearly one-to-one (Liddle 2009).

You might want to discuss the related STIRPAT (Stochastic Impacts by Regression on Population, Affluence, and Technology) framework, which builds on IPAT/impact equation and was introduced by Dietz and Rosa (1997). Dietz and Rosa (1997) proposed a flexible, log-linear, regression framework that allows for hypothesis testing: [equation didn't paste]

where subscripts it denote the ith cross-section and tth time period. The constants and are the country or cross-sectional and time fixed effects, respectively, and is the error term. Affluence (A) is typically proxied by GDP per capita, and the T term is sometimes omitted and other times treated like an intensity of use variable and sometimes modeled as a combination of log-linear factors (like urbanization or density).

Liddle (2014; 2015) provided a summary and critique of the STIRPAT literature. Studies applying the STIRPAT model often estimated population coefficients much greater than one; however, O’Neill et al. (2012) argued that it is not clear why population’s coefficient should be different from one and Liddle (2015) suggested that the large population coefficient estimates could be a symptom of time series/econometric issues.

Dietz, T. and Rosa, E.A. 1997. Effects of population and affluence on CO2 emissions. Proceedings of the National Academy of Sciences – USA, 94, 175-179.

Liddle, B. Long-Run Relation among Transport Demand, Income, and Gasoline Price for the US. Transportation Research D: Transport and Environment, Vol. 14, 2009.

Liddle, B. Impact of Population, Age Structure, and Urbanization on Greenhouse Gas Emissions/Energy Consumption: Evidence from Macro-level, Cross-country Analyses. Population and Environment, Vol. 35, 2014.

Liddle, B. 2015. What Are the Carbon Emissions Elasticities for Income and Population? Bridging STIRPAT and EKC via Robust Heterogeneous Panel Estimates. Global Environmental Change, Vol. 31, pp. 62-73.

O’Neill, B., Liddle, B., Jiang, L., Smith, K., Pachauri, S., Dalton, M., and Fuchs, R. 2012. Demographic change and carbon dioxide emissions. The Lancet, Vol. 380 (9837), pp. 157-164.

We hope Wikipedians on this talk page can take advantage of these comments and improve the quality of the article accordingly.

We believe Dr. Liddle has expertise on the topic of this article, since he has published relevant scholarly research:

• Reference : Liddle, Brantley & Messinis, George, 2014. "Revisiting carbon Kuznets curves with endogenous breaks modeling: Evidence of decoupling and saturation (but few inverted-Us) for individual OECD countries," MPRA Paper 59566, University Library of Munich, Germany.

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I,P,A,T are vectors

About the discussion of how good a description I=PAT is of reality what about making them all matrices with integro-differential elements in arbitrarily non linear relationships? I didn't say more useful, just more general and able to describe reality. The clever proposal is the one where the equations have the right complexity to describe a specific problem, not too complicated not too simple.