Decoupling

The term "decoupling" is used in many different contexts.

Economics

Economic growth without environmental damage

In economic and environmental fields, decoupling is becoming increasingly used in the context of economic production and environmental quality. When used in this way, it refers to the ability of an economy to grow without corresponding increases in environmental pressure. In many economies, increasing production (GDP) raises pressure on the environment. An economy that is able to sustain GDP growth without having a negative impact on environmental conditions, is said to be decoupled. Exactly how, if, or to what extent this can be achieved is a subject of much debate. In 2011, the International Resource Panel, hosted by the United Nations Environment Programme (UNEP) warned that by 2050, the human race could devour 140 billion tons of minerals, ores, fossil fuels and biomass per year – three times its current appetite – unless nations can start decoupling economic growth rates from the rate of natural resource consumption.^[1]. It noted that developed country citizens consume an average of 16 tons of those four key resources per capita (ranging up to 40 or more tons per person in some developed countries). By comparison, the average person in India today consumes four tons per year.

The OECD has made decoupling a major focus of the work of its Environment Directorate. The OECD defines the term as follows: The term 'decoupling' refers to breaking the link between "environmental bads" and "economic goods." It explains this as having rates of increasing wealth greater than the rates of increasing impacts^[2]

Decoupling and the stock market declines of January 2008

Decoupling holds that European and Asian economies, especially emerging ones, have broadened and deepened to the point that they no longer depend on the United States economy for growth, leaving them insulated from a severe slowdown there, even a fully fledged recession. Faith in the concept has generated strong outperformance for stocks outside the United States. However, in January 2008, as fears of recession mounted in the United States, stocks declined heavily. Contrary to what the decouplers would have expected, the losses were greater outside the United States, with the worst experienced in emerging markets and developed economies like Germany and Japan. Exports make up especially large portions of economic activity in those places, but that fact was not supposed to matter anymore in a decoupled world because domestic activity was thought to be so robust.^[3] On the other hand, after the slump the emerging countries experienced a strong recovery, much stronger than that in advanced economies.^[4]

Physical cosmology

In physical cosmology, the term decoupling is often used for the moment during recombination when the rate of Compton scattering became slower than the expansion of the universe. At that moment, photons nearly stopped their interactions with charged matter and "decoupled", producing the cosmic microwave background radiation as we know it. The term decoupling is also used to describe the neutrino decoupling which occurred about one second after the Big Bang. Analogous to the decoupling of photons, neutrinos decoupled when the rate of weak interactions between neutrinos and other forms of matter dropped below the rate of expansion of the universe, which produced a cosmic neutrino background.

Software Development

In software development, the term “decoupling” is used to identify the separation of software blocks that shouldn't depend on each other. Some building blocks are generic and shouldn't know details of others. Special design techniques allow software designers to have as few dependencies as possible. This typically reduces the risk of malfunction in one part of a system when the other part changed. It also forces the developer to focus on one thing at a time.

Decoupling lowers or minimizes Coupling.

Biology

In biology, decoupling (used interchangeably with uncoupling) refers to the separation of the energy stored in the ion gradients inside mitochondria from the synthesis of ATP. Since this energy is not used to do work, it is dissipated as heat. This strategy is used by hibernating animals and infants to keep warm because their heat energy needs are higher than their ATP needs. Artificial decoupling has been used as a diet aid, often with disastrous results.

Neuropsychopharmacology

In neuropsychopharmacology, uncoupling (or decoupling) is a term often used to describe when receptor or ligand binding sites/domains become separated or move alignments or become internalised as a result of drug tolerance to exposure over a period of time to a pharmacologically active psychoactive substance or toxin.

Electronics

In electronics, decoupling refers to the preventing of undesired coupling between subsystems via the power supply connections. This is commonly accomplished by connecting localized capacitors close to the power leads of integrated circuits to act as a small localized energy reservoir; these supply the circuit with current during transient, high current demand periods, preventing the voltage on the power supply rail from being pulled down by the momentary current load. See decoupling capacitor.

Lossy ferrite beads may also be used to isolate or 'island' sections of circuitry. These add a high series impedance (in contrast to the low parallel impedance added by decoupling capacitors) to the power supply rails, preventing high-frequency currents being drawn from elsewhere in the system.

Rail transport

In rail transport, decoupling is the separation of two railroad cars by manipulation of their couplers.

Inventory management

In Inventory Management, decoupling allows economy of scale within a single facility, and permits each process to operate at maximum efficiency rather than having the speed of the entire process constrained by the slowest.

Nuclear testing

In underground nuclear weapons testing, decoupling refers to the attempt to prevent some of the bomb's energy from transmitting as seismic waves. This makes it more difficult for outside observers to estimate the nuclear yield of the weapon being tested.

Mathematics

In mathematics, decoupling has several meanings.

In linear algebra, decoupling refers to the rearrangement of systems of equations so that they are independent of each other.

In probability and statistics, decoupling refers to a reduction of a sample statistic to an average of the statistic evaluated on several independent sequences of the random variable. This sum, conditioned on all but one of the independent sequences becomes a sum of independent random variables. Decoupling is used in the study of U statistics, where decoupling should not be confused with Hoeffding's decomposition, however.^[5] This use of "decoupling" is unrelated to the use of "couplings" in the study of stochastic processes.

In analysis, decoupling refers to the sum of derivatives of a function $f: \R^n \to \R^k\!$ with respect to all the arguments. It can be viewed as the functional that minimizes the Lie derivative of the function f along all the possible paths. Together with the super-trowel function, it is one of the most used tool in the analysis of general equilibrium in economics.

Utility Regulation

Main article: Decoupling plus

In public utility regulation, decoupling refers to the disassociation of a utility's profits from its sales of the energy commodity. Instead, a rate of return is aligned with meeting revenue targets, and rates are trued up or down to meet the target at the end of the adjustment period. This makes the utility indifferent to selling less product and improves the ability of energy efficiency and distributed generation to operate within the utility environment.

Ideally, utilities should be rewarded based on how well they meet their customers' energy service needs. However, most current rate designs place the focus on commodity sales instead, tying a distribution company's recovery of fixed costs directly to its commodity sales.

In order to motivate utilities to consider all the options when planning and making resource decisions on how to meet their customers' needs, the sales-revenue link in current rate design must be broken. Breaking that link between the utility's commodity sales and revenues, removes both the incentive to increase electricity sales and the disincentive to run effective energy efficiency programs or invest in other activities that may reduce load. Decision-making then refocuses on making least-cost investments to deliver reliable energy services to customers even when such investments reduce throughput. The result is a better alignment of shareholder and customer interests to provide for more economically and environmentally efficient resource decisions.

As an added benefit, breaking the sales-revenue link streamlines the regulatory process for rate adjustments. Contention over sales forecasts consumes extensive time in every rate case. If the sales-revenue link is broken, these forecasts carry no economic weight, so the incentive to game forecasts of electricity sales is removed and rate cases become less adversarial.

For an in-depth discussion on decoupling see: Revenue Regulation and Decoupling, Lazar, et al., The Regulatory Assistance Project (2011) ^[6]

While many environmentalists and conservation advocates support decoupling, many consumer advocates representing utility ratepayers have opposed decoupling as it attempts to guarantee revenue levels to utility companies. Decoupling mechanisms reduce a utility company's financial risk from reducing sales, due to conservation, weather and economic conditions. As a result, many consumer advocates have requested and state and federal regulators have required that utility companies profit levels (measured through a return on equity allowance) be reduced to reflect lower risk.

Advertising

Decoupling in advertising is the process whereby advertisers buy services direct from suppliers which were previously sub-contractors to their advertising agencies. Decoupling is discussed in "Magic and Logic" www.magicandlogic.co.uk, the booklet prepared for the Value Framework Steering Group which is a joint venture by the UK trade bodies CIPS, IPA and ISBA.

Decoupling is part of the unbundling of the services previously provided by traditional full service advertising agencies, which originally began with the creation of standalone media buying agencies such as Zenith from Saatchi & Saatchi Group in the '80's and Mindshare from WPP group in the '90's. For the same reasons as media (focus, economies of scale and dedicated software) press production and digital production are now increasingly handled by standalone Production Agencies, which trade direct with advertisers and not through their advertising agencies.

Organizational Studies

In organizational studies, and particularly new institutional theory, the term "decoupling" refers to the creation and maintenance of gaps between formal policies and actual organizational practices.^[7] Organizational researchers have documented decoupling in a variety of organizations, including schools,^[8][9] corporations,^[10] government agencies,^[11] and social movement organizations.^[12] Scholars have proposed a number of explanations for why organizations engage in decoupling. Some researchers have argued that decoupling enables organizations to gain legitimacy with their external members while simultaneously maintaining internal flexibility to address practical considerations.^[7] More recently, scholars have noted that decoupling may occur because it serves the interests of powerful organizational leaders,^[10] or because it allows organizational decision-makers to avoid implementing policies that conflict with their ideological beliefs.^[11]

Meteorology

In weather forecasting the term "decoupling" usually refers to boundary layer decoupling of atmospheric layers over land at night. During the day when the sun shines and warms the land, air at the surface of the earth is heated and rises. This rising air mixes the atmosphere near the earth. At night this process stops and air near the surface cools as the land loses heat by radiating in the infrared. If winds are light, the air near the surface of the earth can become colder than the air above, and 'decouple' from the air above it. When this occurs the air near the surface can become much colder than when decoupling (and better mixing of air layers) does not occur.

Spectroscopy

Nuclear magnetic resonance decoupling in nuclear magnetic resonance (NMR) spectroscopy is a method of simplifying resulting spectrum by irradiating the sample at a certain frequency or frequency range to eliminate fully or partially the effect of coupling between certain nuclei.

See also

• Coupler
• Coupling (disambiguation)
• Object-oriented programming

References

1. ^ Decoupling: natural resource use and environmental impacts of economic growth. International Resource Panel report, 2011
2. ^ OECD 2002 “Indicators to Measure Decoupling of Environmental Pressure from Economic Growth” (excerpt) http://www.oecd.org/dataoecd/0/52/1933638.pdf
3. ^ "Decoupling: Theory vs. reality." International Herald Tribune. January 27, 2008. http://www.iht.com/articles/2008/01/27/business/26delink.php
4. ^ Krugman, Paul (2010-11-09). "We Are Not The World". The New York Times. http://krugman.blogs.nytimes.com/2010/11/09/we-are-not-the-world/. 
5. ^ Victor H. de la Peña and Evariste Giné (1999). Decoupling: From Dependence to Independence. Springer Verlag. 
6. ^ Revenue Regulation and Decoupling, Lazar, et al, The Regulatory Assistance Project (2011)
7. ^ ^{a b} Meyer, John W., and Brian Rowan. 1977. "Institutionalized Organizations: Formal Structure as Myth and Ceremony," American Journal of Sociology, 83: 340-63.
8. ^ Meyer, John W., and Brian Rowan. 1978. "The Structure of Educational Organizations." In M. W. Meyer (ed.), Environments and Organizations. San Francisco: Jossey-Bass
9. ^ Delucchi, Michael. 2000. "Staking a Claim: The Decoupling of Liberal Arts Mission Statements from Baccalaureate Degrees Awarded in Higher Education. Sociological Inquiry. 70: 157-71.
10. ^ ^{a b} Westphal, James D., and Edward Zajac. 2001. "Explaining Institutional Decoupling: The Case of Stock Repurchase Programs." Administrative Science Quarterly, 46: 202-28.
11. ^ ^{a b} Tilcsik, Andras. "From Ritual to Reality: Demography, Ideology, and Decoupling in a Post-Communist Government Agency." 2010. Academy of Management Journal, 53: 6, 1474-1498. Abstract
12. ^ Elsbach, Kimberly D., and Robert Sutton. 1992. "Acquiring Organizational Legitimacy through Illegitimate Actions: A Marriage of Institutional and Impression Management Theories." Academy of Management Journal, 35: 699-738.