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Posts Tagged ‘Lorenz Curve’

Inequality and economic growth

What is the relationship between the degree of inequality in a country and the rate of economic growth? The traditional answer is that there is a trade off between the two. Increasing the rewards to those who are more productive or who invest encourages a growth in productivity and capital investment, which, in turn, leads to faster economic growth. Redistribution from the rich to the poor, by contrast, is argued to reduce incentives by reducing the rewards from harder work, education, training and investment. Risk taking, it is claimed, is discouraged.

Recent evidence from the OECD and the IMF, however, suggests that when income inequality rises, economic growth falls. Inequality has grown massively in many countries, with average incomes at the top of the distribution seeing particular gains, while many at the bottom have experienced actual declines in real incomes or, at best, little or no growth. This growth in inequality can be seen in a rise in countries’ Gini coefficients. The OECD average Gini coefficient rose from 0.29 in the mid-1980s to 0.32 in 2011/12. This, claims the OECD, has led to a loss in economic growth of around 0.35 percentage points per year.

But why should a rise in inequality lead to lower economic growth? According to the OECD, the main reason is that inequality reduces the development of skills of the lower income groups and reduces social mobility.

By hindering human capital accumulation, income inequality undermines education opportunities for disadvantaged individuals, lowering social mobility and hampering skills development.

The lower educational attainment applies both to the length and quality of education: people from poorer backgrounds on average leave school or college earlier and with lower qualifications.

But if greater inequality generally results in lower economic growth, will a redistribution from rich to poor necessarily result in faster economic growth? According to the OECD:

Anti-poverty programmes will not be enough. Not only cash transfers but also increasing access to public services, such as high-quality education, training and healthcare, constitute long-term social investment to create greater equality of opportunities in the long run.

Thus redistribution policies need to be well designed and implemented and focus on raising incomes of the poor through increased opportunities to increase their productivity. Simple transfers from rich to poor via the tax and benefits system may, in fact, undermine economic growth. According to the IMF:

That equality seems to drive higher and more sustainable growth does not in itself support efforts to redistribute. In particular, inequality may impede growth at least in part because it calls forth efforts to redistribute that themselves undercut growth. In such a situation, even if inequality is bad for growth, taxes and transfers may be precisely the wrong remedy.

Articles
Inequality ‘significantly’ curbs economic growth – OECD BBC News (9/12/14)
Is inequality the enemy of growth? BBC News, Robert Peston (6/10/14)
Income inequality damages growth, OECD warns Financial Times, Chris Giles (8/10/14)
OECD finds increasing inequality lowers growth Deutsche Welle, Jasper Sky (10/12/14)
Revealed: how the wealth gap holds back economic growth The Guardian, Larry Elliott (9/12/14)
Inequality Seriously Damages Growth, IMF Seminar Hears IMF Survey Magazine (12/4/14)
Warning! Inequality May Be Hazardous to Your Growth iMFdirect, Andrew G. Berg and Jonathan D. Ostry (8/4/11)
Economic growth more likely when wealth distributed to poor instead of rich The Guardian, Stephen Koukoulas (4/6/15)
So much for trickle down: only bold reforms will tackle inequality The Guardian, Larry Elliott (21/6/15)

Videos
Record inequality between rich and poor OECD on YouTube (5/12/11)
The Price of Inequality The News School on YouTube, Joseph Stiglitz (5/10/12)

Reports and papers
FOCUS on Inequality and Growth OECD, Directorate for Employment, Labour and Social Affairs (December 2014)
Trends in Income Inequality and its Impact on Economic Growth OECD Social, Employment and Migration Working Papers, Federico Cingano (9/12/14)
An Overview of Growing Income Inequalities in OECD Countries: Main Findings OCED (2011)
Redistribution, Inequality, and Growth IMF Staff Discussion Note, Jonathan D. Ostry, Andrew Berg, and Charalambos G. Tsangarides (February 2014)
Measure to Measure Finance and Development, IMF, Jonathan D. Ostry and Andrew G. Berg (Vol. 51, No. 3, September 2014)

Data
OECD Income Distribution Database: Gini, poverty, income, Methods and Concepts OECD
The effects of taxes and benefits on household income ONS

Questions

  1. Explain what are meant by a Lorenz curve and a Gini coefficient? What is the relationship between the two?
  2. The Gini coefficient is one way of measuring inequality. What other methods are there? How suitable are they?
  3. Assume that the government raises taxes to finance higher benefits to the poor. Identify the income and substitution effects of the tax increases and whether the effects are to encourage or discourage work (or investment).
  4. Distinguish between (a) progressive, (b) regressive and (c) proportional taxes?
  5. How will the balance of income and substitution effects vary in each of the following cases: (a) a cut in the tax-free allowance; (b) a rise in the basic rate of income tax; (c) a rise in the top rate of income tax? How does the relative size of the two effects depend, in each case, on a person’s current income?
  6. Identify policy measures that would increase both equality and economic growth.
  7. Would a shift from direct to indirect taxes tend to increase or decrease inequality? Explain.
  8. By examining Tables 3, 26 and 27 in The Effects of Taxes and Benefits on Household Income, 2012/13, (a) explain the difference between original income, gross income, disposable income and post-tax income; (b) explain the differences between the Gini coefficients for each of these four categories of income in the UK.
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Even more dwarfs and fewer but larger giants

In his 1971 book, Income Distribution, Jan Pen, a Dutch economist, gave a graphic illustration of inequality in the UK. He described a parade of people marching by. They represent the whole population and the parade takes exactly one hour to pass by. The height of each person represents his or her income. People of average height are the people with average incomes – the observer is of average height. The parade starts with the people on the lowest incomes (the dwarfs), and finishes with those on the highest incomes (the giants).

Because income distribution is unequal, there are many tiny people. Indeed, for the first few minutes of the parade, the marchers are so small they can barely be seen. Even after half an hour, when people on median income pass by, they are barely waist high to the observer.

The height is growing with tantalising slowness, and forty-five minutes have gone by before we see people of our own size arriving. To be somewhat more exact: about twelve minutes before the end the average income recipients pass by.

In the final minutes, giants march past and then in the final seconds:

the scene is dominated by colossal figures: people like tower flats. Most of them prove to be businessmen, managers of large firms and holders of many directorships and also film stars and a few members of the Royal Family.

The rear of the parade is brought up by a few participants who are measured in miles. Indeed they are figures whose height we cannot even estimate: their heads disappear into the clouds and probably they themselves do not even know how tall they are.

Pen’s description could be applied to most countries – some with even more dwarfs and even fewer but taller giants. Generally, over the 43 years since the book was published, countries have become less equal: the giants have become taller and the dwarfs have become smaller.

The 2011 Economist article, linked below, uses changes in Gini coefficients to illustrate the rise in income inequality. A Gini coefficient shows the area between the Lorenz curve and the 45° line. The figure will be between 0 and 1 (or 0% and 100%). a figure of 0 shows total equality; a figure of 1 shows a situation of total inequality, where one person earns all the nation’s income. The higher the figure, the greater the inequality.

The chart opposite shows changes in the Gini coefficient in the UK (see Table 27 in the ONS link below for an Excel file of the chart). As this chart and the blog post Rich and poor in the UK show, inequality rose rapidly during the years of the 1979–91 Thatcher government, and especially in the years 1982–90. This was associated with cuts in the top rate of income tax and business deregulation. It fell in the recession of the early 1990s as the rich were affected more than the poor, but rose with the recovery of the mid- to late 1990s. It fell again in the early 2000s as tax credits helped the poor. It fell again following the financial crisis as, once more, the rich were affected proportionately more than the poor.

The most up-to-date international data for OECD countries can be found on the OECD’s StatExtracts site (see chart opposite: click here for a PowerPoint). The most unequal developed county is the USA, with a Gini coefficient of 0.389 in 2012 (see The end of the American dream?), and US inequality is rising. Today, the top 1% of the US population earns some 24% of national income. This compares with just 9% of national income in 1976.

Many developing countries are even less equal. Turkey has a Gini coefficient of 0.412 and Mexico of 0.482. The figure for South Africa is over 0.6.

When it comes to wealth, distribution is even less equal. The infographic, linked below, illustrates the position today in the USA. It divides the country into 100 equal-sized groups and shows that the top 1% of the population has over 40% of the nation’s wealth, whereas the bottom 80% has only 7%.

So is this inequality of income and wealth desirable? Differences in wages and salaries provide an incentive for people to work harder or more effectively and to gain better qualifications. The possibility of increased wealth provides an incentive for people to invest.

But are the extreme differences in wealth and income found in many countries today necessary to incentivise people to work, train and invest? Could sufficient incentives exist in more equal societies? Are inequalities in part, or even largely, the result of market imperfections and especially of economic power, where those with power and influence are able to use it to increase their own incomes and wealth?

Could it even be the case that excessive inequality actually reduces growth? Are the huge giants that exist today accumulating too much financial wealth and creating too little productive potential? Are they spending too little and thus dampening aggregate demand? These arguments are considered in some of the articles below. Perhaps, by paying a living wage to the ‘tiny’ people on low incomes, productivity could be improved and demand could be stimulated.

Infographic
Wealth Inequality in America YouTube, Politizane (20/11/12)

Articles
The rise and rise of the cognitive elite The Economist (20/1/11)
Inequality in America: Gini in the bottle The Economist (26/11/13)
Pen’s Parade: do you realize we’re mostly dwarves? LVTFan’s Blog (21/2/11)
Here Are The Most Unequal Countries In The World Business Insider, Andy Kiersz (8/11/14)
Inequality in the World Dollars & Sense, Arthur MacEwan (Nov/Dec 14)
Britain is scared to face the real issue – it’s all about inequality The Observer, Will Hutton (19/1/14)
The tame inequality debate FundWeb, Daniel Ben-Ami (Nov 14)
Is inequality the enemy of growth? BBC News, Robert Peston (6/10/14)

Data
GINI index World Bank data
List of countries by income equality Wikipedia
The Effects of Taxes and Benefits on Household Income, 2012/13 ONS (see table 27)
Income Distribution and Poverty: Gini (disposale income) OECD StatExtract

Questions

  1. Distinguish between income and wealth. Is each one a stock or a flow?
  2. Explain how (a) a Lorenz curve and (b) a Gini coefficient are derived.
  3. What other means are there of measuring inequality of income and wealth other than using Gini coefficients (and giants and dwarfs!)?
  4. Why has inequality been rising in many countries over the years?
  5. How do (a) periods of rapid economic growth and (b) recessions affect income distribution?
  6. Define ‘efficiency wages’. How might an increase in wages to people on low incomes result in increased productivity?
  7. What is the relationship between the degree of inequality and household debt? What implications might this have for long-term economic growth and future financial crises? Is inequality the ‘enemy of growth’?
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Rich and poor in the UK

The ONS has just released its annual publication, The Effects of Taxes and Benefits on Household Income. The report gives data for the financial year 2012/13 and historical data from 1977 to 2012/13.

The publication looks at the distribution of income both before and after taxes and benefits. It divides the population into five and ten equal-sized groups by household income (quintiles and deciles) and shows the distribution of income between these groups. It also looks at distribution within specific categories of the population, such as non-retired and retired households and different types of household composition.

The data show that the richest fifth of households had an average pre-tax-and-benefit income of £81,284 in 2012/13, 14.7 times greater than average of £5536 for the poorest fifth. The richest tenth had an average pre-tax-and-benefit income of £104,940, 27.1 times greater than the average of £3875 for the poorest tenth.

After the receipt of cash benefits, these gaps narrow to 6.6 and 11.0 times respectively. When the effect of direct taxes are included (giving ‘disposable income’), the gaps narrow further to 5.6 and 9.3 times respectively. However, when indirect taxes are also included, the gaps widen again to 6.9 and 13.6 times.

This shows that although direct taxes are progressive between bottom and top quintiles and deciles, indirect taxes are so regressive that the overall effect of taxes is regressive. In fact, the richest fifth paid 35.1% of their income in tax, whereas the poorest fifth paid 37.4%.

Taking the period from 1977 to 2012/13, inequality of disposable income (i.e. income after direct taxes and cash benefits) increased from 1977 to 1988, especially during the second two Thatcher governments (1983 to 1990) (see chart opposite). But then in the first part of the 1990s inequality fell, only to rise again in the late 1990s and early 2000s. However, with the Labour government giving greater cash benefits for the poor, inequality reduced once more, only to widen again in the boom running up to the banking crisis of 2007/8. But then, with recession taking hold, the incomes of many top earners fell and automatic stabilisers helped protect the incomes of the poor. Inequality consequently fell. But with the capping of benefit increases and a rise in incomes of many top earners as the economy recovers, so inequality is beginning to rise once more – in 2012/13, the Gini coefficient rose to 0.332 from 0.323 the previous year.

As far as income after cash benefits and both direct and indirect taxes is concerned, the average income of the richest quintile relative to that of the poorest quintile rose from 7.2 in 2002/3 to 7.6 in 2007/8 and then fell to 6.9 in 2012/13.

Other headlines in the report include:

Since the start of the economic downturn in 2007/08, the average disposable income has decreased for the richest fifth of households but increased for the poorest fifth.

Cash benefits made up over half (56.4%) of the gross income of the poorest fifth of households, compared with 3.2% of the richest fifth, in 2012/13.

The average disposable income in 2012/13 was unchanged from 2011/12, but it remains lower than at the start of the economic downturn, with equivalised disposable income falling by £1200 since 2007/08 in real terms. The fall in income has been largest for the richest fifth of households (5.2%). In contrast, after accounting for inflation and household composition, the average income for the poorest fifth has grown over this period (3.5%).

This is clearly a mixed picture in terms of whether the UK is becoming more or less equal. Politicians will, no doubt, ‘cherry pick’ the data that suit their political position. In general, the government will present a good news story and the opposition a bad news one. As economists, it is hoped that you can take a dispassionate look at the data and attempt to relate the figures to policies and events.

Report
The Effects of Taxes and Benefits on Household Income, 2012/13 ONS (26/6/14)

Data
Reference tables in The Effects of Taxes and Benefits on Household Income, 2012/13 ONS (26/6/14)
The Effects of Taxes and Benefits on Household Income, Historical Data, 1977-2012/13 ONS (26/6/14)
Rates of Income Tax: 1990-91 to 2014-15 HMRC

Articles
Inequality is on the up again – Osborne’s boast is over New Statesman, George Eaton (26/6/14)
Disposable incomes rise for richest fifth households only Money.com, Lucinda Beeman (26/6/14)
Half of families receive more from the state than they pay in taxes but income equality widens as rich get richer Mail Online, Matt Chorley (26/6/14)
Rich getting richer as everyone else is getting poorer, Government’s own figures reveal Mirror, Mark Ellis (26/6/14)
The Richest Households Got Richer Last Year, While Everyone Else Got Poorer The Economic Voice (27/6/14)

Questions

  1. Define the following terms: original income, gross income, disposable income, post-tax income, final income.
  2. How does the receipt of benefits in kind vary across the quintile groups? Explain.
  3. What are meant by the Lorenz curve and the Gini coefficient and how is the Gini coefficient measured? Is it a good way of measuring inequality?
  4. Paint a picture of how income distribution has changed over the past 35 years.
  5. Can changes in tax be a means of helping the poorest in society?
  6. What types of income tax cuts are progressive and what are regressive?
  7. Why are taxes in the UK regressive?
  8. Why has the fall in income been largest for the richest fifth of households since 2007/8? Does this mean that, as the economy recovers, the richest fifth of households are likely to experience the fastest increase in disposable incomes?
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Growing inequality in Russia

Inequality is growing in most countries. This can be illustrated by examining what has been happening to countries’ Gini coefficient. The Gini coefficient measures income inequality, where 0.00 represents perfect equality, with everyone in the country earning the same, and 1.00 represent perfect inequality, with one person earning all the country’s income. (Note that sometimes it is expressed as the ‘Gini index’, with 100 representing perfect inequality). In virtually all countries, the Gini coefficient has been rising. In the OECD countries it has risen by an average of 0.3% per annum over the past 25 years. The OECD average is now 0.31.

But despite the fact that the Gini coefficient has been rising, its value differs markedly from one country to another, as does its rate of change. For example, Finland’s Gini coefficient, at 0.26, is below the average, but it has been rising by 1.2% per annum. By contrast, Turkey’s Gini coefficient, at 0.41, is above the average and yet has been falling by 0.3% per annum.

The most unequal of the developed countries is the USA. According to OECD data, its Gini coefficient is 0.38, well above the values in the UK (0.34), Japan (0.33), Germany (0.30) France (0.29) and Denmark (0.26). What is more, inequality in the USA has been increasing by an average of 0.5% per annum since the mid 1980s.

According to the United Nations’ Human Development Report 2010, the USA’s Gini coefficient is even higher, at 0.41 (see Table 3 of the report). But this is still below that of Russia, with a figure of 0.44, a figure that has markedly worsened over time, along with those of other former Soviet countries. According to the report (page 72):

The worsening is especially marked in countries that were part of the former Soviet Union – which still have relatively low Gini coefficients because they started with low inequality. Transition has eroded employment guarantees and ended extensive state employment. Before the fall of the Berlin Wall, 9 of 10 people in socialist countries were employed by the state, compared with 2 of 10 in Organisation for Economic Co-operation and Development economies. While the privileged elite (the nomenklatura) often attained higher material well-being, the measured differences in income were narrow.

The Gini coefficient for Russia is the same as the average of the 39 developing countries with the lowest level of human development &nbash; and developing countries are generally much less equal than developed ones. Of course, some developing countries have an even higher Gini coefficient: for Angola the figure is 0.59; for Haiti it is 0.60.

The following three webcasts look at aspects of the growing inequality in Russia.

Webcasts
Gap between rich and poor widens in Russia BBC News, Jamie Robertson (29/5/11)
Corruption slows Russian modernisation BBC News, Emma Simpson (29/5/11)
Corruption and poverty in Russia’s far east Al Jazeera (28/2/11)

Articles
Russia’s rich double their wealth, but poor were better off in 1990s Guardian, Tom Parfitt (11/4/11)
Russia’s growing wealth gap BBC News, Jamie Robertson (28/5/11)
A Country of Beggars and Choosers Russia Profile, Svetlana Kononova (16/5/11)
Rich and poor, growing apart The Economist (3/5/11)

Data
Distribution of family income – Gini Index CIA World Factbook (ranked by country in desending order)
Society at a Glance 2011 – OECD Social Indicators OECD: see particularly the Excel file 6. Equity Indicators: Income inequality (click on No if prompted about a linked workbook)
Russia Distribution of family income – Gini index Index Mundi
Chart of the week: inflation stoking inequality in China and India Financial Times, Andrew Whiffin (24/5/11)
List of countries by income equality Wikipedia

Reports
Growing Income Inequality in OECD Countries: What Drives it and How Can Policy Tackle it? OECD Forum on Tackling Inequality (2/5/11)
Human Development Report 2010 United Nations Development Programme

Questions

  1. Explain what is meant by the Gini coefficient. How does it relate to the Lorenz curve? What does a figure of 0.31 mean?
  2. Why has income inequality been growing in most countries of the world? Has the process of globalisation dampened or exacerbated this trend?
  3. What specific factors in Russia can explain the growing inequality?
  4. How is privatisation likely to affect income distribution??
  5. Why is it difficult to quantify the extent of inequality in Russia?
  6. What maxim of taxation has been used in setting income tax rates in Russia?
  7. What role does corruption play in determining the degree of inequality in Russia?
  8. What policy measures, if any, could realistically be adopted in Russia to reduce inequality? What constraints are there on adopting such policies?
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Income distribution – more or less equal?

Since Labour has been in power the gap between rich and poor has remained more or less unchanged – a fact that might be surprising given a Labour government and fiscal policies that have become increasingly redistributive in nature. In fact income distribution in the UK has not changed since 1991 according to Office for National Statistics figures. Economists measure income distribution in various ways, but two of the key indicators are the Gini coefficient and the Lorenz curve. For more information on income distribution and some useful data, you may like to download an income data spreadsheet from the IFS (zip file). If you are interested in where you fit into the income scale, then you may also like to try the Institute for Fiscal Studies interactive income model. Why not try a range of different scenarios to see where different levels of income fit into the overall income scale.

UK income gap ‘same as in 1991′ BBC News Online (16/12/08)

Questions

  1. Define the terms (a) Gini coefficient and (b) Lorenz curve.
  2. Using diagrams as appropriate, show how the Lorenz curve will change when income distribution becomes (a) more equal and (b) less equal.
  3. Explain how the value of the Gini coefficient will change as income distribution gets more equal. With reference to the IFS spreadsheet (linked to above) descibe how the Gini coefficient has changed in recent years.
  4. Discuss reasons why income distibution in the UK has stayed the same since 1991 despite a series of redistributive measures adopted by the Labour government since 1997.
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It’s getting more super being super-rich

Globalisation has reduced the bargaining power of unskilled workers and pushed up inequality in many western countries, the OECD said, urging governments to improve their social safety nets.” With the gap between rich and poor widening once again, the media have been considering the impact of widening income and wealth distribution. The articles below look at this widening gap and also at the ways in which the rich are using their money.

Gap between rich and poor widens Guardian (20/6/07)
For the super-rich it’s all give and take – at record levels Guardian (20/6/07)
Looking after the super-rich BBC News Online (Evan Davis blog) (9/8/07)

Questions
1. Define what is meant by the terms (i) Lorenz curve and (ii) Gini coefficient.
2. Using illustrations as appropriate, show how the Lorenz curve and the value of the Gini coefficient have changed in the past decade.
3. Assess the likely impact on the major macroeconomic targets of growing income inequality.
4. Discuss policies that the government could put in place to try to reduce the level of income inequality.
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“All people are equal, but some are more equal than others” – life gets less equal

During the period that Mrs Thatcher was in office, the post-war trend towards greater equality of income was reversed. Although some of the changes the Labour government has made since 1997 have helped those on lower incomes, the rise in incomes at the top of the scale has meant that the gap between rich and poor has widened again. The article below from the Guardian looks at the latest figures on income inequality.

Inequality at same level as under Thatcher Guardian (18/5/07)


Questions
1. Define the terms (a) Lorenz curve and (b) Gini coefficient.
2. Given the changes in income distribution outlined in the article, discuss how the value of the Gini coefficient has changed since 1997.
3. Draw Lorenz curves to show the changes that have taken place in income distribution during Mrs Thatcher’s period in office and during Tony Blair’s time in office.
4. Analyse two policies that the government could introduce to reverse these income distribution trends.
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