Overblog Suivre ce blog
Editer l'article Administration Créer mon blog
3 décembre 2013 2 03 /12 /décembre /2013 04:56

The Steering Group on the implementation of the Strategic Energy Technologies Plan (SET Plan) on 26 June 2008 will set the agenda for an EU energy technology policy. It will enhance the coordination of national and European research and innovation efforts to position the EU in the forefront of the low-carbontechnologies markets. Toshiba Satellite M70-122 CPU Fan

The European Energy Research Alliance (EERA)[16] is founded by the leading research institutes in the European Union (EU), to expand and optimise EU energy research capabilities through the sharing of world-class national facilities and the joint realisation of national and European programmes. SONY UDQFWPH22FQU CPU Fan

This new Research Alliance will be a key actor of the EU Strategic Energy Technology Plan (SET Plan) and will contribute to accelerate the development of new low carbontechnologies for EU to move toward a low carbon economy.

Under the requirements of the Directive on Electricity Production from Renewable Energy Sources, HP Pavilion dv6-2150ei CPU Fan

which entered into force in October 2001, the member states are expected to meet "indicative" targets for renewable energy production. Although there is significant variation in national targets, the average is that 22% of electricity should be generated by renewables by 2010 (compared to 13,9% in 1997). HP G42-367TU CPU Fan

The European Commission has proposed in its Renewable Energy Roadmap21 a binding target of increasing the level of renewable energy in the EU's overall mix from less than 7% today to 20% by 2020.

At the Heiligendamm Summit in June 2007, the G8 acknowledged an EU proposal for an international initiative on energy efficiency tabled in March 2007, Toshiba Satellite P100-238 CPU Fan

and agreed to explore, together with the International Energy Agency, the most effective means to promote energy efficiency internationally. A year later, on 8 June 2008, the G8 countries, China, India, South Korea and the European Community decided to establish the International Partnership for Energy Efficiency Cooperation, ACER Aspire 5739 CPU Fan

at the Energy Ministerial meeting hosted by Japan in the frame of the 2008 G8 Presidency, in Aomori.Buildings account for around 40% of EU energy requirements and have been the focus of several initiatives.[24] From 4 January 2006, the 2002 Directive on the energy performance of buildings[25] requires member states to ensure that new buildings, IBM ThinkPad T40 2678 CPU Fan

as well as large existing building undergoing refurbishment, meet certain minimum energy requirements. It also requires that all buildings should undergo 'energy certification' prior to sale, and that boilers and air conditioning equipment should be regularly inspected.

As part of the EU's SAVE Programme,[26] aimed at promoting energy efficiency and encouraging energy-saving behaviour, IBM Thinkpad T43 CPU Fan

the Boiler Efficiency Directive[27] specifies minimum levels of efficiency for boilers fired with liquid or gaseous fuels. Originally, from June 2007, all homes (and other buildings) in the UK would have to undergo Energy Performance Certification before they are sold or let,[28] to meet the requirements of the European Energy Performance of Buildings Directive (Directive 2002/91/EC). IBM ThinkPad T43 2668 CPU Fan

Carbon dioxide emissions from transport have risen rapidly in recent years, from 21% of the total in 1990 to 28% in 2004.[30]

EU policies include the voluntary ACEA agreement, signed in 1998, to cut carbon dioxide emissions for new cars sold in Europe to an average of 140 grams of CO2/km by 2008, a 25% cut from the 1995 level. IBM ThinkPad T43 1871 CPU Fan

Because the target was unlikely to be met, the European Commission published new proposals in February 2007, requiring a mandatory limit of 130 grams of CO2/km for new cars by 2012, with 'complementary measures' being proposed to achieve the target of 120 grams of CO2/km that had originally been expected.[31][32] ACER Travelmate 8104WLMI CPU Fan

In the area of fuels, the 2001 Biofuels Directive requires that 5,75% of all transport fossil fuels (petrol and diesel) should be replaced by biofuels by 31 December 2010, with an intermediate target of 2% by the end of 2005. In February 2007 the European Commission proposed that, DELL Latitude E4300 CPU Fan

from 2011, suppliers will have to reduce carbon emissions per unit of energy by 1% a year from 2010 levels, to result in a cut of 10% by 2020 Stricter fuel standards to combat climate change and reduce air pollution.

Beyond the bounds of the European Union, EU energy policy has included negotiating and developing wider international agreements, ASUS F80S CPU Fan

such as the Energy Charter Treaty, the Kyoto Protocol, the post-Kyoto regime and a framework agreement on energy efficiency; extension of the EC energy regulatory framework or principles to neighbours (Energy Community, Baku Initiative, Euro-Med energy cooperation) and the emission trading scheme to global partners; the promotion of research and the use of renewable energy.[37] HP Pavilion dv5-1058eo CPU Fan

The EU-Russia energy cooperation will be based on a new comprehensive framework agreement within the post-Partnership and Cooperation Agreement (PCA), which will be negotiated in 2007. The energy cooperation with other third energy producer and transit countries is facilitated with different tools, such as the PCAs, IBM 13N5182 CPU Fan

the existing and foreseen Memorandums of Understanding on Energy Cooperation (with Ukraine, Azerbaijan, Kazakhstan and Algeria), the Association Agreements with Mediterranean countries, theEuropean Neighbourhood Policy Action Plans; Euromed energy cooperation; the Baku initiative; IBM Thinkpad T30 2366-AA3 CPU Fan

and the EU-Norway energy dialogue.[37]For the cooperation with African countries, a comprehensive Africa-Europe Energy partnership would be launched at the highest level, with the integration of Europe's Energy and Development Policies.[6]

For ensuring efficient follow-up and coherence in pursuing the initiatives and processes, IBM Thinkpad T30 CPU Fan

for sharing information in case of an external energy crisis, and for assisting the EU's early response and reactions in case of energy security threats, the network of energy correspondents in the Member States was established in early 2007. After the Russian-Ukrainian Gas Crisis of 2009 the EU decided that the existing external measures regarding gas supply security should be HP 535438-001 CPU Fan

supplemented by internal provisions for emergency prevention and response, such as enhancing gas storage and network capacity or the development of the technical prerequisites for reverse flow in transit pipelines

The European Union is also active in the areas of energy research, development and promotion, via initiatives such as CEPHEUS (ultra-low energy housing), DELL Inspiron N3010 CPU Fan

and programs under the umbrella titles of SAVE (energy saving) ALTENER (new and renewable energy sources), STEER (transport) and COOPENER (developing countries).[40]Through Fusion for Energy, the EU is participating in the ITER project

The European Commission imposed anti-dumping levies on Chinese solar panel imports in June 2013.[39] HP Pavilion dv6-3070tx CPU Fan

As reported earlier China was selling solar panels under production costs that made the operation without return also for the Chinese solar power companies. Chinese government guaranteed the operation of Chinese solar power companies.

In a poll carried out for the European Commission in October and November 2005, IBM 41W5269 CPU Fan

47% of the citizens questioned in the 27 countries of the EU (including the 2 states that joined in 2007) were in favour of taking decisions on key energy policy issues at a European level. 37% favoured national decisions and 8% that they be tackled locally.[42]

A similar survey of 29 220 people in March and May 2006 indicated that the balance had changed in favour of national decisions in these areas (42% in favour), ASUS A8H CPU Fan

with 39% backing EU policy making and 12% preferring local decisions. There was significant national variation with this, with 55% in favour in the Netherlands, but only 15% in Finland

The Gini coefficient (also known as the Gini index or Gini ratio) (/dʒini/) is a measure of statistical dispersion intended to represent the income distribution of a nation's residents. SONY UDQFRZH13CF0 CPU Fan

It was developed by theItalian statistician and sociologist Corrado Gini and published in his 1912 paper "Variability and Mutability" (Italian: Variabilità e mutabilità).[1][2]

The Gini coefficient measures the inequality among values of a frequency distribution (for example levels ofincome). A Gini coefficient of zero expresses perfect equality, HP COMPAQ 2510P CPU Fan

where all values are the same (for example, where everyone has an exactly equal income). A Gini coefficient of one (or 100%) expresses maximal inequality among values (for example where only one person has all the income).[3][4] However, a value greater than one may occur if some persons have negative income or wealth. APPLE 661-4951 CPU Fan

For larger groups, values close to or above 1 are very unlikely in practice.

Gini coefficient is commonly used as a measure of inequality of income or wealth.[5] For OECD countries, in the late 2000s, considering the effect of taxes and transfer payments, the income Gini coefficient ranged between 0.24 to 0.49, with Slovenia the lowest and Chile the highest.[6] HP Pavilion dv6-3034ca CPU Fan

The countries in Africa had the highest pre-tax Gini coefficients in 2008–2009, with South Africa the world's highest at 0.7.[7][8] The global income inequality Gini coefficient in 2005, for all human beings taken together, has been estimated to be between 0.61 and 0.68 by various sources.[9][10]

There are some issues in interpreting a Gini coefficient. HP G56-126NR CPU Fan

The same value may result from many different distribution curves. The demographic structure should be taken into account. Countries with an aging population, or with a baby boom, experience an increasing pre

The Gini coefficient is usually defined mathematically based on the Lorenz curve, Compaq Presario C556CA CPU Fan

which plots the proportion of the total income of the population (y axis) that is cumulatively earned by the bottom x% of the population (see diagram). The line at 45 degrees thus represents perfect equality of incomes. The Gini coefficient can then be thought of as the ratio of the area that lies between the line of equality and the Lorenz curve (marked A in the diagram) SONY Vaio VGN-NR360E CPU Fan

over the total area under the line of equality (marked A and B in the diagram); i.e., G = A / (A + B).

If all people have non-negative income (or wealth, as the case may be), the Gini coefficient can theoretically range from 0 to 1; it is sometimes expressed as a percentage ranging between 0 and 100. In practice, both extreme values are not quite reached. HP Pavilion dv5170us CPU Fan

If negative values are possible (such as the negative wealth of people with debts), then the Gini coefficient could theoretically be more than 1. Normally the mean (or total) is assumed positive, which rules out a Gini coefficient less than zero.

A low Gini coefficient indicates a more equal distribution, with 0 corresponding to complete equality, SONY Vaio VPC-EE3WFX/WI CPU Fan

while higher Gini coefficients indicate more unequal distribution, with 1 corresponding to complete inequality. When used as a measure of income inequality, the most unequal society (assuming no negative incomes) will be one in which a single person receives 100% of the total income and the remaining people receive none (G = 1−1/N); HP G56-126NR CPU Fan

and the most equal society will be one in which every person receives the same income (G = 0).

An alternative approach would be to consider the Gini coefficient as half of the relative mean difference, which is a mathematical equivalence. The mean difference is the average absolute difference between two items selected randomly from a population, HP 3MLX8TATP20 CPU Fan

and the relative mean difference is the mean difference divided by the average, to normalize for scale.

Given the normalization of both the cumulative population and the cumulative share of income used to calculate the Gini coefficient, the measure is not overly sensitive to the specifics of the income distribution, but rather only on how incomes vary relative to the other members of a population. SONY Vaio VGN-NW240F/S CPU Fan

The exception to this is in the redistribution of wealth resulting in a minimum income for all people. When the population is sorted, if their income distribution were to approximate a well known function, then some representative values could be calculated. Some representative values of the Gini coefficient for income distributions approximated by some simple functions are tabulated below. SONY Vaio VPC-EB1Z0E/B CPU Fan

While the income distribution of any particular country need not follow such simple functions, these functions give a qualitative understanding of the income distribution in a nation given the Gini coefficient. The effects of minimum income policy due to redistribution can be seen in the linear relationships above. Compaq Presario CQ60-514NR CPU Fan

Gini coefficients of income are calculated on market income as well as disposable income basis. The Gini coefficient on market income – sometimes referred to as pre-tax Gini index – is calculated on income before taxes and transfers, and it measures inequality in income without considering the effect of taxes and social spending already in place in a country. Toshiba Satellite X205-S9800 CPU Fan

The Gini coefficient on disposable income – sometimes referred to as after-tax Gini index – is calculated on income after taxes and transfers, and it measures inequality in income after considering the effect of taxes and social spending already in place in a country.[6][16][17]

The difference in Gini indices between OECD countries, on after-taxes and transfers basis, ASUS G2P CPU Fan

is significantly narrower.[ For OECD countries, over 2008–2009 period, Gini coefficient on pre-taxes and transfers basis for total population ranged between 0.34 to 0.53, with South Korea the lowest and Italy the highest. Gini coefficient on after-taxes and transfers basis for total population ranged between 0.25 to 0.48, with Denmark the lowest and Mexico the highest. Compaq Presario CQ60-430SA CPU Fan

For United States, the country with the largest population in OECD countries, the pre-tax Gini index was 0.49, and after-tax Gini index was 0.38, in 2008–2009. The OECD averages for total population in OECD countries was 0.46 for pre-tax income Gini index and 0.31 for after-tax income Gini Index.[6][18] DELL BFB0505HA CPU Fan

Taxes and social spending that were in place in 2008–2009 period in OECD countries significantly lowered effective income inequality, and in general, "European countries — especially Nordic and Continental welfare states — achieve lower levels of income inequality than other countries."[19] HP Pavilion dv5-1272et CPU Fan

Using the Gini can help quantify differences in welfare and compensation policies and philosophies. However it should be borne in mind that the Gini coefficient can be misleading when used to make political comparisons between large and small countries or those with different immigration policies (see limitations of Gini coefficient section). Toshiba AB7005HX-SB3 CPU Fan

The Gini index for the entire world has been estimated by various parties to be between 0.61 and 0.68.The graph shows the values expressed as a percentage, in their historical development for a number of countries.For the late 2000s, the United States had the 4th highest measure of income inequality out of the 34 OECD countries measured, after taxes and transfers had been taken into account.[21] Toshiba Satellite A500-18T CPU Fan

The table below presents the Gini indices for household income, without including the effect of taxes and transfers, for the United Statesat various times, according to the US Census Bureau.[22][23][24][25]The Gini values are a national composite, with significantvariations in Gini between the states. HP Pavilion dv5-2135dx CPU Fan

The states of Utah, Alaska and Wyoming have a pre-tax income inequality Gini coefficient that is 10% lower than the U.S. average, while Washington D.C. and Puerto Rico 10% higher. After including the effects of federal and state taxes, the U.S. Federal Reserve estimates 34 states in the USA have a Gini coefficient between 0.30 and 0.35, with the state of Maine the lowest.[26] ASUS EEE PC 1201NL CPU Fan

At the county and municipality levels, the pre-tax Gini index ranged from 0.21 to 0.65 in 2010 across the United States, according to Census Bureau estimates.

According to UNICEF, Latin America and the Caribbean region had the highest net income Gini index in the world at 48.3, on unweighted average basis in 2008. SONY Vaio VGN-NW240D/T CPU Fan

The remaining regional averages were: sub-Saharan Africa (44.2), Asia (40.4), Middle East and North Africa (39.2), Eastern Europe and Central Asia (35.4), and High-income Countries (30.9). Using the same method, the United States is claimed to have a Gini index of 36, while South Africa had the highest income Gini index score of 67.8. Compaq Presario CQ60-418DX CPU Fan

The table below presents the estimated world income Gini index over the last 200 years, as calculated by Milanovic.[30] Taking income distribution of all human beings, the worldwide income inequality has been constantly increasing since the early 19th century. There was a steady increase in global income inequality Gini score from 1820 to 2002, SONY Vaio VGN-NW240D CPU Fan

with a significant increase between 1980 and 2002. This trend appears to have peaked and begun a reversal with rapid economic growth in emerging economies, particularly in the large populations ofBRIC countries.

Education Gini index estimates the inequality in education for a given population.[34] SONY VGN-BX197XP CPU Fan

It is used to discern trends in social development through educational attainment over time. From a study of 85 countries, Thomas et al. estimate Mali had the highest education Gini index of 0.92 in 1990 (implying very high inequality in education attainment across the population), while the United States had the lowest education inequality Gini index of 0.14. Toshiba Satellite L645D-S4056 CPU Fan

Between 1960 and 1990, South Korea, China and India had the fastest drop in education inequality Gini Index. They also claim education Gini index for the United States slightly increased over the 1980 – 1990 period.

Similar in concept to income Gini coefficient, opportunity Gini coefficient measures inequality of opportunity.[35Toshiba AB7805HX-GB3 CPU Fan

The concept builds on Amartya Sen's suggestion[38] that inequality coefficients of social development should be premised on the process of enlarging people’s choices and enhancing their capabilities, rather than process of reducing income inequality. Toshiba Satellite L500-208 CPU Fan

Kovacevic in a review of opportunity Gini coefficient explains that the coefficient estimates how well a society enables its citizens to achieve success in life where the success is based on a person’s choices, efforts and talents, not his background defined by a set of predetermined circumstances at birth, such as, gender, race, place of birth, parent's income and circumstances beyond the control of that individual. HP 535441-001 CPU Fan

In 2003, Roemer reported Italy and Spain exhibited the largest opportunity inequality Gini index amongst advanced economies.

In 1978, A. Shorrocks introduced a measure based on income Gini coefficients to estimate income mobility.[40] This measure, generalized by Maasoumi and Zandvakili,[41] Toshiba Satellite P100-444 CPU Fan

is now generally referred to as Shorrocks index, sometimes as Shorrocks mobility index or Shorrocks rigidity index. It attempts to estimate whether the income inequality Gini coefficient is permanent or temporary, and to what extent a country or region enables economic mobility to its people so that they can move from one (e.g. bottom 20%) income quantile to another HP Pavilion dv7-3114eo CPU Fan

(e.g. middle 20%) over time. In other words, Shorrocks index compares inequality of short-term earnings such as annual income of households, to inequality of long-term earnings such as 5-year or 10-year total income for same households.

Shorrocks index is calculated in number of different ways, a common approach being from the ratio of income Gini coefficients between short-term and long-term for the same region or country.[42] HP Mini 110-1125SA CPU Fan

A 2010 study using social security income data for the United States since 1937 and Gini-based Shorrocks indexes concludes that its income mobility has had a complicated history, primarily due to mass influx of women into the country's labor force after World War II. Income inequality and income mobility trends have been different for men and women workers between 1937 and the 2000s. HP KSB06105HA CPU Fan

When men and women are considered together, the Gini coefficient-based Shorrocks Index trends imply long-term income inequality has been substantially reduced among all workers, in recent decades for the United States.[42] Other scholars, using just 1990s data or other short periods have come to different conclusions.[43] Compaq Presario CQ60-210eo CPU Fan

For example, Sastre and Ayala, conclude from their study of income Gini coefficient data between 1993 and 1998 for six developed economies, that France had the least income mobility, Italy the highest, and the United States and Germany intermediate levels of income mobility over those 5 years. HP Pavilion dv7-2250sf CPU Fan

Gini coefficient has features that make it useful as a measure of dispersion in a population, and inequalities in particular.[45] It is a ratio analysis method making it easier to interpret. It also avoids references to a statistical average or position unrepresentative of most of the population, such as per capita income or gross domestic product. HP 434678-001 CPU Fan

For a given time interval, Gini coefficient can therefore be used to compare diverse countries and different regions or groups within a country; for example states, counties, urban versus rural areas, gender and ethnic groups. Gini coefficients can be used to compare income distribution over time, thus it is possible to see if inequality is increasing or decreasing independent of absolute incomes. HP G60-230us CPU Fan

The Gini coefficient is a relative measure. Its proper use and interpretation is controversial.[49] Mellor explains[50] it is possible for the Gini coefficient of a developing country to rise (due to increasing inequality of income) while the number of people in absolute poverty decreases. This is because the Gini coefficient measures relative, HP Pavilion dv6365us CPU Fan

not absolute, wealth. Kwok concludes[51] that changing income inequality, measured by Gini coefficients, can be due to structural changes in a society such as growing population (baby booms, aging populations, increased divorce rates, extended family households splitting into nuclear families, emigration, immigration) and income mobility. HP 535439-001 CPU Fan

Gini coefficients are simple, and this simplicity can lead to oversights and can confuse the comparison of different populations; for example, while both Bangladesh (per capita income of $1,693) and the Netherlands (per capita income of $42,183) had an income Gini index of 0.31 in 2010,[52] COMPAQ 6910c CPU Fan

the quality of life, economic opportunity and absolute income in these countries are very different, i.e. countries may have identical Gini coefficients, but differ greatly in wealth. Basic necessities may be available to all in a developed economy, while in an undeveloped economy with the same Gini coefficient, basic necessities may be unavailable to most or unequally available, due to lower absolute wealth. IBM Lenovo IdeaPad G510 CPU Fan

Even when the total income of a population is the same, in certain situations two countries with different income distributions can have the same Gini index (e.g. cases when income Lorenz Curves cross).[45] Table A illustrates one such situation. Both countries have a Gini index of 0.2, but the average income distributions for household groups are different. HP G62-110SO CPU Fan

As another example, in a population where the lowest 50% of individuals have no income and the other 50% have equal income, the Gini coefficient is 0.5; whereas for another population where the lowest 75% of people have 25% of income and the top 25% have 75% of the income, the Gini index is also 0.5. DELL Precision M6400 CPU Fan

Economies with similar incomes and Gini coefficients can have very different income distributions. Bellù and Liberati claim that to rank income inequality between two different populations based on their Gini indices is sometimes not possible, or misleading.

A Gini index does not contain information about absolute national or personal incomes. SONY Vaio VPC-EB290X CPU Fan

Populations can have very low income Gini indices, yet simultaneously very high wealth Gini index. By measuring inequality in income, the Gini ignores the differential efficiency of use of household income. By ignoring wealth (except as it contributes to income) the Gini can create the appearance of inequality when the people compared are at different stages in their life. HP Envy 17-1090eo CPU Fan

Wealthy countries such as Sweden can show a low Gini coefficient for disposable income of 0.31 thereby appearing equal, yet have very high Gini coefficient for wealth of 0.79 to 0.86 thereby suggesting an extremely unequal wealth distribution in its society.[54][55] These factors are not assessed in income-based Gini. Toshiba Satellite A210-1CF CPU Fan

Gini index has a downward-bias for small populations.[56] Counties or states or countries with small populations and less diverse economies will tend to report small Gini coefficients. For economically diverse large population groups, a much higher coefficient is expected than for each of its regions. Taking world economy as one, and income distribution for all human beings, Dell Vostro 3450 CPU Fan

for example, different scholars estimate global Gini index to range between 0.61 and 0.68.[9][10] As with other inequality coefficients, the Gini coefficient is influenced by the granularity of the measurements. For example, five 20% quantiles (low granularity) will usually yield a lower Gini coefficient than twenty 5% quantiles (high granularity) for the same distribution. Toshiba Satellite A10-103 CPU Fan

Philippe Monfort has shown that using inconsistent or unspecified granularity limits the usefulness of Gini coefficient measurements.[57]

The Gini coefficient measure gives different results when applied to individuals instead of households, for the same economy and same income distributions. Compaq Presario A900 CTO CPU Fan

If household data is used, the measured value of income Gini depends on how the household is defined. When different populations are not measured with consistent definitions, comparison is not meaningful.

Deininger and Squire (1996) show that income Gini coefficient based on individual income, rather than household income, are different. ACER Aspire 4736ZG CPU Fan

For United States, for example, they find that individual income-based Gini index was 0.35, while for France they report individual income-based Gini index to be 0.43. According to their individual focussed method, in the 108 countries they studied, South Africa had the world's highest Gini index at 0.62, Toshiba Satellite A10-103 CPU Fan

Malaysia had Asia's highest Gini index at 0.5, Brazil the highest at 0.57 in Latin America and Caribbean region, and Turkey the highest at 0.5 in OECD countries.

Expanding on the importance of life-span measures, the Gini coefficient as a point-estimate of equality at a certain time, ignores life-span changes in income. SONY MCF-519PAM05 CPU Fan

Typically, increases in the proportion of young or old members of a society will drive apparent changes in equality, simply because people generally have lower incomes and wealth when they are young than when they are old. Because of this, factors such as age distribution within a population and mobility within income classes can create the appearance of inequality when none exist taking into account demographic effects. SONY Vaio VPC-EB290X CPU Fan

Thus a given economy may have a higher Gini coefficient at any one point in time compared to another, while the Gini coefficient calculated over individuals' lifetime income is actually lower than the apparently more equal (at a given point in time) economy's.[13] Essentially, what matters is not just inequality in any particular year, but the composition of the distribution over time. HP Pavilion dv7-2043cl CPU Fan

Kwok claims income Gini index for Hong Kong has been high (0.434 in 2010[52]), in part because of structural changes in its population. Over recent decades, Hong Kong has witnessed increasing numbers of small households, elderly households and elderly living alone. The combined income is now split into more households. HP Pavilion dv7-2130ev CPU Fan

Many old people are living separately from their children in Hong Kong. These social changes have caused substantial changes in household income distribution. Income Gini coefficient, claims Kwok, does not discern these structural changes in its society.[51] Household money income distribution for the United States, HP 608772-001 CPU Fan

summarized in Table C of this section, confirms that this issue is not limited to just Hong Kong. According to the US Census Bureau, between 1979 and 2010, the population of United States experienced structural changes in overall households, the income for all income brackets increased in inflation-adjusted terms, household income distributions shifted into higher income brackets over time, while the income Gini coefficient increased.[59][60] Toshiba Satellite A100-194 CPU Fan

Another limitation of Gini coefficient is that it is not a proper measure of egalitarianism, as it is only measures income dispersion. For example, if two equally egalitarian countries pursue different immigration policies, the country accepting a higher proportion of low-income or impoverished migrants will report a higher Gini coefficient and therefore may appear to exhibit more income inequality. HP Pavilion tx1205/ CT CPU Fan

Arnold describes one limitation of Gini coefficient to be income distribution situations where it misleads. The income of poorest fifth of households can be lower when Gini coefficient is lower, than when the poorest income bracket is earning a larger percentage of all income. Table D illustrates this case, HP Pavilion dv6640ep CPU Fan

where the lowest income bracket has an average household market income of $500 per year at Gini index of 0.51, and zero income at Gini index of 0.48. This is counter-intuitive and Gini coefficient cannot tell what is happening to each income bracket or the absolute income, cautions Arnold.[61][62] COMPAQ Presario CQ42-401TU CPU Fan

Feldstein similarly explains one limitation of Gini coefficient as its focus on relative income distribution, rather than real levels of poverty and prosperity in society.[63] He claims Gini coefficient analysis is limited because in many situations it intuitively implies inequality that violate the so-called Pareto improvement principle. Toshiba Satellite A300D CPU Fan

The Pareto improvement principle, named after the Italian economist Vilfredo Pareto, states that a social, economic or income change is good if it makes one or more people better off without making anyone else worse off. Gini coefficient can rise if some or all income brackets experience a rising income. Feldstein’s explanation is summarized in Table D. HP Pavilion dv8397ea CPU  Fan

The table shows that in a growing economy, consistent with Pareto improvement principle, where income of every segment of the population has increased, from one year to next, the income inequality Gini coefficient can rise too. In contrast, in another economy, if everyone gets poorer and is worse off, income inequality is less and Gini coefficient lower. HP Pavilion dv9821ea CPU Fan

Some countries distribute benefits that are difficult to value. Countries that provide subsidized housing, medical care, education or other such services are difficult to value objectively, as it depends on quality and extent of the benefit. In absence of free markets, valuing these income transfers as household income is subjective. HP COMPAQ TC4200 CPU Fan

The theoretical model of Gini coefficient is limited to accepting correct or incorrect subjective assumptions.In subsistence-driven and informal economies, people may have significant income in other forms than money, for example through subsistence farming orbartering. These income tend to accrue to the segment of population that is below-poverty line or very poor, SONY Vaio VGN-NW228F CPU Fan

in emerging and transitional economy countries such as those in sub-Saharan Africa, Latin America, Asia and Eastern Europe. Informal economy accounts for over half of global employment and as much as 90 per cent of employment in some of the poorer sub-Saharan countries with high official Gini inequality coefficients. HP G62-b16ST CPU Fan

Schneider et al., in their 2010 study of 162 countries,[66] report about 31.2%, or about $20 trillion, of world's GDP is informal. In developing countries, the informal economy predominates for all income brackets except for the richer, urban upper income bracket populations. Even in developed economies, between 8% (United States) to 27% (Italy) of each nation's GDP is informal, HP 580696-001 CPU Fan

and resulting informal income predominates as a livelihood activity for those in the lowest income brackets.[67] The value and distribution of the incomes from informal or underground economy is difficult to quantify, making true income Gini coefficients estimates difficult.[63][64] Different assumptions and quantifications of these incomes will yield different Gini coefficients.[ HP Pavilion dv6-3049tx CPU Fan

Gini has some mathematical limitations as well. It is not additive and different sets of people cannot be averaged to obtain the Gini coefficient of all the people in the sets.Given the limitations of Gini coefficient, other statistical methods are used in combination or as an alternative measure of population dispersity. For example,entropy measures are frequently used (e.g. the Theil Index and the Atkinson index). HP G42-380LA CPU Fan

These measures attempt to compare the distribution of resources by intelligent agents in the market with a maximum entropy random distribution, which would occur if these agents acted like non-intelligent particles in a closed system following the laws of statistical physics.

Although the Gini coefficient is most popular in economics, it can in theory be applied in any field of science that studies a distribution. Toshiba Qosmio G30-167 CPU Fan

For example, in ecology the Gini coefficient has been used as a measure of biodiversity, where the cumulative proportion of species is plotted against cumulative proportion of individuals.[75] In health, it has been used as a measure of the inequality of health related quality of life in a population.[76] In education, it has been used as a measure of the inequality of universities.[77] HP Pavilion dv7-1157cl CPU Fan

In chemistry it has been used to express the selectivity of protein kinase inhibitors against a panel of kinases.[78] In engineering, it has been used to evaluate the fairness achieved by Internet routers in scheduling packet transmissions from different flows of traffic.[79] In statistics, building decision trees, it is used to measure the purity of possible child nodes, Compaq Presario CQ40-408AX CPU Fan

with the aim of maximising the average purity of two child nodes when splitting, and it has been compared with other equality measures.[80]

The Gini coefficient is sometimes used for the measurement of the discriminatory power of rating systems in credit risk management.[81] HP Mini 110-1110ET CPU Fan

The discriminatory power refers to a credit risk model's ability to differentiate between defaulting and non-defaulting clients. The formula  , in calculation section above, may be used for the final model and also at individual model factor level, to quantify the discriminatory power of individual factors. It is related to accuracy ratio in population assessment models. HP Pavilion dv7-1157cl CPU Fan

A diversity index is a quantitative measure that reflects how many different types (such as species) there are in a dataset, and simultaneously takes into account how evenly the basic entities (such as individuals) are distributed among those types. The value of a diversity index increases both when the number of types increases and when evenness increases. HP Pavilion dv6-3163eo CPU Fan

For a given number of types, the value of a diversity index is maximized when all types are equally abundant.When diversity indices are used in ecology, the types of interest are usually species, but they can also be other categories, such as genera, families,functional types or haplotypes. The entities of interest are usually individual plants or animals, HP Pavilion dv9740us CPU Fan

and the measure of abundance can be, for example, number of individuals, biomass or coverage. In demography, the entities of interest can be people, and the types of interest various demographic groups. In information science, the entities can be characters and the types the different letters of the alphabet. HP COMPAQ NX9420 CPU Fan

The most commonly used diversity indices are simple transformations of the effective number of types (also known as 'true diversity'), but each diversity index can also be interpreted in its own right as a measure corresponding to some real phenomenon (but a different one for each diversity index). HP Pavilion dv7-4150ec CPU Fan

True diversity, or the effective number of types, refers to the number of equally-abundant types needed for the average proportional abundance of the types to equal that observed in the dataset of interest (where all types may not be equally abundant). The true diversity in a dataset is calculated by first taking the weighted generalized mean of the proportional abundances of the types in the dataset, and then taking the inverse of this. HP Pavilion dv5-1102tu CPU Fan

The denominator equals average proportional abundance of the types in the dataset as calculated with the weighted generalized mean with exponent q - 1. In the equation, R is richness (the total number of types in the dataset), and the proportional abundance of the ith type is . The proportional abundances themselves are used as the nominal weights. SONY VGN-SZ220 CPU Fan

he value of q is often referred to as the order of the diversity. It defines the sensitivity of the diversity value to rare vs. abundant species by modifying how the mean of the species proportional abundances is calculated. With some values of the parameter q, the generalized mean with exponent q - 1 gives familiar kinds of mean as special cases. HP Pavilion dv7-6011tx CPU Fan

In particular, q = 0 corresponds to the harmonic mean, q = 1 to the geometric mean and q = 2 to the arithmetic mean. As qapproaches infinity, the generalized mean with exponent q - 1 approaches the maximum   value, which is the proportional abundance of the most abundant species in the dataset. HP Pavilion dv5-1040eb CPU Fan

In practice, increasing the value of q hence increases the effective weight given to the most abundant species. This leads to obtaining a larger mean   value and a smaller true diversity (qD) value.When q = 1, the geometric mean of the   values is used, and each species is exactly weighted by its proportional abundance (in the geometric mean, weights are the exponents). ASUS F3Jv CPU Fan

When q > 1, the weight given to abundant species is exaggerated, and when q < 1, the weight given to rare species is. At q = 0, the species weights exactly cancel out the species proportional abundances, such that mean   equals 1/R even when all species are not equally abundant. At q = 0, the effective number of species (0D) hence equals the actual number of species (R). IBM ThinkPad R50p 2887 CPU Fan

In the context of diversity, q is generally limited to non-negative values. This is because negative values of q would give rare species so much more weight than abundant ones that qD would exceed R.

Richness R simply quantifies how many different types the dataset of interest contains. SONY VGN-CS36GJ/R CPU Fan

For example, species richness (usually notated S) of a dataset is the number of different species in the corresponding species list. Richness is a simple measure, so it has been a popular diversity index in ecology, where abundance data are often not available for the datasets of interest. Toshiba Satellite A215-S4807 CPU Fan

Because richness does not take the abundances of the types into account, it is not the same thing as diversity, which does take abundances into account. However, if true diversity is calculated with q = 0, the effective number of types (0D) equals the actual number of types (R).

The Shannon index has been a popular diversity index in the ecological literature, Toshiba Satellite Pro M10-SP405 CPU Fan

where it is also known as Shannon's diversity index, the Shannon-Wiener index, the Shannon-Weaver index and the Shannon entropy. The measure was originally proposed by Claude Shannon to quantify the entropy (uncertainty or information content) in strings of text.[5] The idea is that the more different letters there are, HP Pavilion dv4-1120us CPU Fan

and the more equal their proportional abundances in the string of interest, the more difficult it is to correctly predict which letter will be the next one in the string. The Shannon entropy quantifies the uncertainty (entropy or degree of surprise) associated with this prediction.

In ecology,   is often the proportion of individuals belonging to the ith species in the dataset of interest. Compaq Presario C550EM CPU Fan

Then the Shannon entropy quantifies the uncertainty in predicting the species identity of an individual that is taken at random from the dataset.

Although the equation is here written with natural logarithms, the base of the logarithm used when calculating the Shannon entropy can be chosen freely. Toshiba Qosmio E15-AV101 CPU Fan

Shannon himself discussed logarithm bases 2, 10 and e, and these have since become the most popular bases in applications that use the Shannon entropy. Each log base corresponds to a different measurement unit, which have been called binary digits (bits), decimal digits (decits) and natural digits (nats) for the bases 2, 10 and e, respectively. Toshiba Satellite L645D-S4056 CPU Fan

Comparing Shannon entropy values that were originally calculated with different log bases requires converting them to the same log base: change from the base a to base b is obtained with multiplication by logbaToshiba Satellite A305-S6837 CPU Fan,HP Pavilion dv7-4087cl CPU Fan,HP Pavilion dv5-1118es CPU Fan

Partager cet article

Repost 0
Published by batterys
commenter cet article