the economic elements of income inequality
TRANSCRIPT
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The Economic Elements of Income Inequality
BSc (Hons) Economics and Business Finance
Social School of Sciences
Student Number: 1230887
Word count: 8,114
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Abstract:
This thesis studies the relationship of certain variables towards income inequality and measures
the significance and effect of these variables have on inequality. Inequality has a negative impact
on economic growth, making it essential to be able to control it. The study is based in 21
European countries over 21 years, 1992-2012. A cross-sectional panel data is used to estimate
the effects on inequality. Also a fixed country effect is set on the regression to eliminate the
constant variance of the countries being analysed. A discussion being raised by this paper is that
whether countries in the European Union have a lower inequality compared to countries outside
the European Union and inside Europe.
Acknowledgements:
A special thank you to Dr. Corrado Macchiarelli for his very valuable help towards this paper
and to my parents for the constant support.
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Contents
Part I Introduction .................................. 4
Part II Literature Review ................................... 5
1. Education ........................................................................................ 5
2. Trade Liberation .............................................................................. 7
3. Recent Trends in Income Inequality ................................................ 8
4. Tax ................................................................................................ 10
5. Inflation ........................................................................................ 11
Part III Data ................................... 12
1. Data .............................................................................................. 12
2. Descriptive Statistics ..................................................................... 13
3. Correlation Analysis .................................................................... 14
Part IV Methodology ................................. 15
Part V Results ...................................... 17
Part XI Conclusion ................................... 20
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Part I Introduction
Income inequality is the extent to which income is unevenly distributed among a population. It is
not a pretty sight for any economy. A highly uneven distribution in income can lead to a negative
impact on economic incentives, possibly slow down growth and it simply undercuts the ideal that
we, humans, were all created as equal and should live in an egalitarian society.
In the United Kingdom, Equalitytrust shows that only 0.1% of the U.K population earns £1
million while 10% earn £79,196 and the other 90% all make, on average, £12,969. A more
surprising statistic is that the average full-time pay for a CEO at a FTSE 100 company is a
staggering £4.3 million compared to the average U.K worker who received only £26,500. The
Gini Coefficient measured income inequality to be 0.24 in 1977 and increased to 0.34 in 2012
making the U.K the most unequal developed country, in terms of income. This shows how
income inequality does have a strong effect on the economy and if inequality had not changed
since 1977 the majority of the working population in the U.K would be earning more.
Strong government intervention could diminish inequality, through their tax systems and
expenditure on its economy. Increasing progressive tax rate is a very effective system of
equaling the rich with the poor. This dissertation sets out to find to what extent certain variables
such as education, growth and tax can affect income inequality. It also discusses if low inequality
is achieved by countries in the European Union compared to European countries outside the
European Union.
According to many economists, such as Perotti (1996), income inequality has a negative impact
on economic growth. It can also play an important role on the drive in financial development and
political stability. Since inequality can interfere with factors such as economic growth and
development, it is crucial to comprehend on how to affect and control inequality so as the
economy could potentially be better off.
There are different factors that may have an effect on income distribution and different methods
of reducing inequality. In the labor market, wages will be higher for jobs that require skilled
workers that are low in supply compared to jobs that require non-skilled workers that are high in
supply. This creates income inequality, being the gap between wages earned by non-skilled
workers to wages earned by skilled workers. One of the main factors that play the central role in
shaping up income inequality is education. An increase or improvement in education, of an
economy, helps increase the supply of skilled workers hence decreasing the wage premium of
high skilled workers through the law of demand and supply. This could be adjusted until the
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demand and supply of labor reach equilibrium, meaning skilled workers receive the same wage
as non-skilled workers, and income will be evenly distributed among the population eliminating
any inequality in income. Although the point of equilibrium is impossible to reach in terms of the
real economy, as it is just a model, it does have a comparable impact towards the economy.
Along with education, there are many other factors that affect inequality from globalization to
urbanization to crime and health. However this thesis will look at influences that play its part on
inequality through only an economic perspective.
Although there are many methods used to measure inequality, the Gini Coefficient is widely
used around the world and is taken as the primary indices in many of the past literature and
studies. It uses the Lorenz Curve to represent the cumulative percentage of income distribution
on the horizontal axis versus the cumulative number of people in an economy on the vertical
axis. This graphical representation was established by Max O. Lorenz in 1905 to measure
inequality of wealth. Pros of using the Gini coefficient are that it provides availability of the data
and the popular use of the Gini coefficient as a measure of income distribution in past literatures.
However a drawback is that World Bank Data provides a limited amount of data for the Gini
Index. However, this thesis will too use the Gini Coefficient as a measurement of income
distribution.
Part II Literature Review
1. Education
Schultz (1963) states that “increasing human capital as one way to lower income inequality and
increased support for public education might be one way to accomplish this.” Increasing
government expenditure on resources such as public education could potentially lower income
inequality and this is what Kevin Sylwester (2000) sets out to examine. He uses the Gini
Coefficient to measure the income distribution after changes in public education over 20 years.
His study shows that Egypt, Ecuador, France, Turkey and Italy benefited from a 20% decrease in
the Gini Coefficient meaning over the years, improvement in public education led to a decrease
in income inequality. However, Tanzania, Sri Lanka, U.K, Australia and New Zealand all
suffered from a 20% increase in the Gini Coefficient leading to an increase in income equality.
Sylwester’s final result concluded that countries that invest in public education tend to have
lower income inequality in succeeding years although the effect will be shown over the
long-term.
Knight and Sabot (1983) argue that in the short-term there is a composition effect being the
initial increase in inequality due to an in increase in the number of educated workers. However,
over the long-term there will be a compression effect which is the decrease in income inequality
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due to increase in the supply of educated workers and the fall in the wage premium. Their
argument supports the one of Kevin Sylwester (2000).
Abdul Abdullah (2013) conducted an MRA study in order to be able to tell us the average effect
of public education on income inequality. His 64 econometric studies found him that education
reduces the gap between the rich and the poor, hence lowering inequality. His study turned out to
produce more interesting results. He found that some of his results suggest that secondary school
has a more important influence on lowering inequality than primary and higher education.
Therefore, if an economy were in need of lowering inequality then reducing the funds of
secondary education would be effective. However, it should be known that this study is not
robust.
Günther Rehme (2007) stated, through his study of 6 of the G7 countries provided by the
Luxembourg Income Study (LIS), that increases in education first increase and then decrease
growth as well as income inequality, when measured by the Gini coefficient. His conclusion
supports the study of Sylwester (2000), Knight and Sabot (1983) and Abdul Abdullah (2013).
The studies used in these journals all use income inequality as its dependent variable. The
disadvantage here is the possible cause of reverse causation. Sylwester (2003) later on conducted
another study going deeper into the research. He compares the effect on income inequality with a
greater enrolment rate in higher education. Sylwester (2003) states that “what differentiates his
study from the others listed above is the use of the change in income inequality over time as the
dependent variable instead of using the level at a point in time.” He uses the Gini Coefficient to
measure the degree of income inequality. Using 50 observations in his study which was
conducted from 1970-1990, his results concluded that there is negative relation between
enrolment in higher education and income inequality. Therefore, supporting participation in
higher education is predicted to lower income inequality. However, through which higher
education will lower inequality is still unknown.
All in all, although studies were found that education was not highly correlated with inequality, it
can be concluded, with the support of a few economists, that past literature has found that there
does exist a relationship between education and income inequality. During the short-term, reports
show that education increases the gap between the rich and the poor. However, over the
long-term it can be seen that education has a negative impact on income inequality. Therefore,
past studies suggest that the government were to increase its expenditure on public education if
its aim were to lower income inequality. More specifically, through the research of Abdul
Abdullah (2013) and Sylwester (2003), lower income inequality could be met if the government
were to spend on secondary education and if there would be an increase in the participation rate
for higher education.
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2. Trade Liberation
The introduction of globalization could play a big role on how income is distributed among a
nations working population. Whether this process does have an effect on inequality is a
controversy among many economists and many argue that different outcomes will be produced
from different economic situations. According to some authors, both developing and developed
nations suffer from an increase in income inequality. Empirical evidence suggests that there has
been an increase in inequality and slow growth in most countries over the last two decades and
Cornia (1999) argues that globalization is a prime factor in this. Barro (2000) and Wood (1994)
both explain that globalizations lead to an increase in income inequality in developed countries
whereas income would be more evenly distributed among the population of a developing
country.
The trade theory, articulated in the Heckscher–Ohlin (HO) model, shows that developing
countries should experience a more equal trend in inequality as a result of globalization. One
theorem derived from this model is the Stolper–Samuelson (SS) theorem, which is significant as
it measures the relationship between the price of output and the real wage. So, if there is an
increase in the price of labor intensive goods then there will be an increase in real wages as a
result. However, an increase in the price of capital-intensive goods will lead to a decrease in real
wage as more capital is needed rather than labor to carry out the certain investment. In this case,
the introduction of globalization will increase the relative prices of unskilled workers in
developing countries hence leading to a more equal distribution in income. However, there are
too many limitations and assumptions implied towards this model that restricts it from predicting
the real economy.
Bergh and Nilsson (2010) conducted a study using the KOF index of globalization, that measures
the economic, political and social dimensions of globalization, and concludes that trade
liberalization does tend to increase income inequality in developed countries therefore,
supporting the results of Stolper- Samuelson theorem. Social globalization is the major drive of
high inequality for middle- and low-income countries. There are other studies by different
economists that also prove and support the predictions of the SS theorem, which include Wood
(1994) and Calderón and Chong (2001). They argue income inequality is decreased after
globalisation.
However, there stands a strong argument that allowing international trade among developing
countries may result in an increase in income inequality. This is because of the allowance of
developed countries to promote their new and advanced technology towards developing
countries. Therefore, there will be an increase in demand for skillful workers in order to manage
the new technology. This increase in demand for skillful workers, which developing countries
lack, will create a form of income inequality. Lee and Vivarelli (2004, and 2006b) put in their
own words that “if such is the case, then trade – via technology – should imply a counter-effect
to the SS theorem prediction, namely an increase in the demand for skilled labour, an increase in
wage dispersion and so an increase in income inequality.” This study, which contradicts that of
Wood (1994), is also supported by authors such as Barro (2000) and Ravallion (2001).
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Elena Meschi (2009) analyses the impact of trade on the inequality of income using a sample of
65 developed countries between the periods 1980-1999.Unlike previous studies, which were
characterized by cross-section methodology, this focuses on within-country income inequality as
it has shown to be more important in recent times. Her study uses the Heckscher-Ohlin (HO) to
analyse the effect of relative returns to the factor of production, such as Wood (1994). However,
Meschi chooses to relax the assumption of identical technologies across the two countries as this
will lead to the development of the process of technology diffusion across developing countries
through international trade, imports and exports. The more skilled-intensive technologies sent
from the developed country to the developing country will increase the demand for skilled
labour. This upward shift for skilled labour will lead to a more unequal income distribution.
Applying this model to her research shows that, consistent with previous studies, total aggregate
trade flows are not significantly related to within-country income inequality among developing
countries. However, what is interesting in her results is that trade with high-income countries
will increase income inequality in a developing country through imports and exports. Meschi
also states from her results, however not supported with theoretical evidence, that trade within
developing countries will reduce income inequality. Apart from this, Meschi concludes that the
level of human and economic development can impact within-country income inequality in a
developing country. This means that improvement in higher education and training policies in
developing countries will provide a more skilled labour force which will therefore reduce income
inequality.
3. Recent Trends in Income Inequality
Previous sections of this thesis analyse the effect of an independent variable on income
inequality. It shows the possible relationship between certain factors and inequality. In this
section however, changes in the pattern of income inequality will be covered between different
countries over a period of time. It will also study how significant each variable is on the changes
of income inequality.
Around 60 years ago, the average human capital earned enough to have a high standard of living
and be able to raise their family, in the United States. The economy grew at an increasing pace
and the country began to develop over time. 30 years after World War II, the United States had
the largest middle class sector in the world. In these times, the income of the average worker
doubled along with the size of the economy. However over the past 30 years, the size of
economy continued to double while the earnings of the average worker stayed the same. This
form of income inequality created, as what is known today, the Great U-Turn. Previous
literatures study the determinants of what cause this inequality and how this uneven income
distribution would affect the economy as a whole.
Freeman and Katz (1995, p. 13) stress on the fact that during the 1970’s income inequality has
rose drastically in advanced industrial societies, such as the United Kingdom and the United
Sates. This increase in income inequality raised awareness of social science researchers in
different fields. The reasoning behind this was because, firstly, the increase in income inequality
led to a reversal in the long-term decline in income inequality. Also the increase in inequality
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destroyed the Kuznets U-Shaped model which “represents the inverted U-curve relating
inequality to development conjectured by Kuznets” (1955; see also Lindert and Williamson
1985).
Stephanie Moller (2009) examines the change in patterns of income inequality in the United
States over 1970-2000. She also provides reasoning as to what effected income inequality and
how the economy would react. The data collected shows the distribution of family income
among 3098 U.S counties and therefore Moller uses U.S counties as a unit of analysis. County
data provides insight into social mechanisms that are causing inequality while data from
individuals or a national level does not offer that benefit. Her result agrees with Freeman and
Katz (1995) by showing that income inequality does increase significantly in U.S counties over
30 years. By the year 2000, income inequality was as high as the U.S has last experienced it in
late 1920s. The study shows that the strongest factor in rising income inequality is economic
development. There is a U-shaped relationship between economic development and inequality
where economic development in U.S counties initially decline as inequality increases but then
rises over the long-term. Education was recorded as the second strongest factor where counties
with higher levels of education, measured by high school completion, have a less unequal
income distribution compared to counties with lower levels of education. Race and ethnicity is
next in importance. There is a strong longitudinal effect which indicates that counties which had
an increase in the black population saw a more unequal income distribution. This finding shows
that race and ethnicity does contribute in increasing inequality. Other factors are shifts in the
labour force, urbanization, and change in women status and age composition. To conclude, this
journal has reported that the important determinants of income inequality are economic
development, demographic, and political-institutional variables.
Over the past few years, China’s income inequality has far surpassed the level of inequality in
the United States due to a rapid increase. Yu Xie and Xiang Zhou (2014) set out a study to
explain the possible effects of the increase in inequality in China. Data was collected from
the 2010 baseline survey of the China Family Panel Studies (CFPS). The 25 provinces of China
represent around 95% of the Chinese population. The Gini Coefficient increases from 0.530
based on the CFPS in 2010 to 0.611 based on the CFPS in 2011, showing the increase in income
inequality. Yu Xie and Xiang Zhou show that the increase in uneven distribution in income is
due to the urban areas being more preferred to rural areas. Since inequality is very high they
suggest that the government implements a policy that reduces the disparity between rural and
urban areas as to lower inequality.
In conclusion, over the years many developed and developing countries faced a substantial
increase in income inequality. Various factors played a role in rising inequality and this section
shows that different countries are affected by different factors. For example, Stephanie Moller
(2009) finds that inequality rises in the U.S because of an increase in economic development and
from different races and ethnicities in different counties. However, Yu Xie and Xiang Zhou state
that the gap between rural and urban areas raise income inequality in China.
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4. Tax
The tax system is a popular public policy instrument used to adjust income inequality.
In most countries today, income tax is progressive, that is income tax rates raise as income rises.
Theoretically tax has a significant impact on inequality and governments always attempt to
implement the best tax policy to minimize inequality. This section reviews the past literature on
how tax, such as income tax, could be used to control inequality in income of an economy.
Economists as Thon (1987) and Jakobsson (1976) show in their past studies that an increase in
the progressive tax system will evenly distribute income, after-tax, and Fellman (1976) states
that if income is progressively taxed, inequality will decrease.
Peter J. Lambert (1992) focuses his study on how income taxed progressively reduces inequality
and provides conditions that give significant descriptive and prescriptive values. Lambert
believes that a liability of tax occurs from attributes such as ones marital status, household
ownership and income which play a role on income inequality. His theory faces two problems:
1. Decreasing tax rates, towards a married couple for example leads to differences in tax
treatments among the population, towards a single man for instance.
2. The vice-versa effect, where the married couple would be taxed higher, could introduce an
adverse influence on income inequality.
Therefore, Lambert adds few conditions and limitations to motivate this theorem and to prove
that income tax leads to an overall decrease in inequality. His study shows that under the
assumption that the difference in tax treatment is not taken into account in an economy;
progressive income tax is a strong factor in reducing inequality as Fellman (1976) states.
Lambert says that his theory provides no explanation to why income tax reduces income
inequality. He explains his empirical findings illustrate that reduced inequality are the
achievements of tax policy-makers and designers rather than income tax.
Another study by Grace Anyaegbu (2011) shows that government interventions, tax and
subsidiaries, decrease household income in the United States from 1980 to 2010. Surprisingly
taxes made little difference on income inequality over the period. This was because direct taxes
reduced inequality while indirect taxes increase inequality hence almost equally diminishing the
impact on inequality. Her analysis shows that income inequality was reduced between 1980 and
2010 largely because of the increase in subsidiaries rather than tax. Government incentives
decreased inequality by an average of 15 percentage points, in terms of Gini Coefficient, over the
period. However, direct taxes reduced inequality by an average of 3 percentage points and
indirect taxes increased inequality by an average of 4 percentage points. She finds that direct tax
and subsidiaries appear to have a negative effect on income inequality however no relationship
holds between indirect tax and income inequality. Overall government incentives were the main
factor in reducing inequality as the Gini Coefficient shows. The effect of tax on income
inequality is very minimal however Anyaegbu concludes that there was an increase in the
redistributive effect of direct tax which was driven by the tax concentration coefficient therefore
leading to direct tax having only a small effect on lowering income inequality in the United
States.
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In theory, tax plays a significant role in adjusting inequality through tax progression as
Jakobsson (1976) argues. However, this does not seem the case in the real world as studies have
struggled to find strong evidence that supports the existence of the relationship between income
inequality and tax. More specifically, direct tax does have a small effect in lowering inequality
conversely an increase in indirect tax will increase inequality. Study shows that government
intervention through subsidies will be more effective, than direct tax, in lowering inequality
since Gini Coefficients showed to decrease by 15 percentage points compared to the 3
percentage point decrease from direct tax in the United States.
5. Inflation
Inflation is an under-researched topic when analysing the effects it has on income inequality.
This is surprising as the few researches done by Schultz (1969) and Blinder and Esaki (1978)
show that inflation has a recurring influence on income distribution in 12 developed countries.
This could possibly be because there are not many convincing hypotheses other than the simple
Kuznets hypothesis (Kuznets, 1955) which explains the non-linear relationship that exists
between income distribution and economic development. One alternative on measuring the effect
of inflation on inequality is an ad hoc augmentation of the Kuznets model. This alternative
method was established by Milanovic (1994, p.3) who explains “that income distribution is
determined ( 1) by factors that are in the short run, from the point of view of policy makers or
society as a whole, 'given,' and (2) by social (or public policy) choice.”
Using the original data of Milanovic, Aleš Bulíř (2001) uses a cross-country model of 75
countries to analyse the Kuznets hypothesis of income inequality by including inflation. He
states that it is not a coincidence that high inequality was recorded in South America, having
suffered from hyperinflation, and that there was low inequality in Asia where inflation is lower
than average. The study shows that inflation does have a positive effect on inequality and results
were robust. The positive impact of inflation on income inequality is non-linear since countries
who have recovered from hyperinflation had a more significant decrease in inequality compared
to countries already on low inflation rates that benefit less. This was then shown in the results
where countries with inflation rates between 5 to 40 percent achieve a higher decrease in
inequality compared to countries whose inflation rate is lower than 5 percent. He concludes that
disinflation has no negative costs and only benefits by improving income inequality. However it
cannot be compared with other alternative methods as there are only few cross-country studies
have used inflation as an effect on income inequality.
Another study done by Fahim A. Al-Marhubi (2007) agrees with previous studies in that
inflation has a positive impact on inequality. His analysis is based on a cross-country data
consisting 53 countries over the period 1975 to 1995. Data on the variables such as inflation and
high school enrolment are collected from the World Bank Data and inflation is transformed into
the logarithm of the average annual change in GDP spending. The study concluded that inflation
is significantly positively associated with income inequality and the results are robust.
Not much study is invested into the effect of inflation on income inequality therefore it is thought
that inflation does not play a role in adjusting inequality. However, the few studies that were
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applied show that inflation does in fact have a strong positive influence on inequality. Research
shows that countries that suffering from hyperinflation had a higher decrease in inequality when
re-adjusted to a steady rate of inflation compared to countries with lower than average inflation
rate which only had a small decrease in inequality. There are only a few alternate methods other
than the Kuznets hypothesis which is the reasoning to why not many studies were undertaken.
However, most of the studies consistently prove that inflation and inequality have a positive
relation, and to reduce inequality the economy has to reduce its inflation rate.
Part III Data
1. Data
Data for this thesis is collected, based on factors that are the main indicators on effecting income
inequality, from 21 countries in Europe over the period 1992-2012. Data of the Gini Coefficient
are collected from the World Data Bank and Eurostat along with OECD. Data of other variables
such as tax, inflation and education are solely collected from the World Data Bank. As stated
earlier this thesis will use the Gini Coefficient to measure income inequality.
Education is one of the variables that could potentially adjust inequality in an economy. Past
studies have shown that higher high school enrolment leads to a more even distribution in
income. The data collected for education in this thesis are labour forces that have completed
secondary or tertiary education. The inclusion of secondary education along with tertiary is
because previous analysis shows that developing countries lack the household income for tertiary
education and the majority of the population only completed secondary education. Data collected
on education will measure the percentage change in labour force of secondary and tertiary
education and if there exists a significant impact on inequality.
Economic growth is said to be an important factor on income distribution. This thesis uses a
logarithm transformation on the percentage change of GDP per capita as the main indicator to
evaluate what relationship it holds with income inequality. Theoretically most economists agree
that there is a Kuznets relation between growth and inequality. Using the data collected for GDP,
this thesis sets to prove if the same relation holds for countries in Europe or if it plays a more
significant positive role.
Inflation is also another factor affecting income inequality. It is the only variable in this study
that did not need first differencing as it was originally measured as the change in percentage of
consumer price index (CPI). There was lack of data on the World Data Bank therefore data for
inflation was also collected from Eurostat.
The data collected for tax had significant gaps between periods. Therefore, data was interpolated
meaning that data was automatically inputted by roughly calculating the mean between the gaps.
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Income tax was used as the measurement tool between tax and inequality because previous
studies show that income tax is the second most powerful government policy to have a positive
impact on income inequality. Income tax was then transformed to the annual percentage change
in direct tax.
Another influence on inequality is unemployment. Data was collected from the World Data Bank
and the data measures unemployment against the total labour force which is based on the ILO
estimate. It required first differencing so was transformed to the annual change in percentage of
unemployment, out of the labour force.
Growth in population has an indirect effect on income inequality. Population over the age of 65
(% of total population) is used to analyse the significance of population growth on inequality. It
was transformed to the annual change of population over 65 in percentage. This specific variable
was used in this study since an increase in retired human capital lowers inequality.
The effect of trade on inequality is the final variable involved in this study. Openness, through
globalization, allows imports and exports to flow leading to an effect on income inequality.
Therefore data collected for trade is measured as the difference between exports and imports
before being transformed to the annual change in the difference between exports and imports.
2. Descriptive Statistics
Descriptive statistics generally summarizes and defines the data that has been collected. The
standard deviation of most the variables in the result are significantly high. This indicates that the
data is not concentrated and is farther away from the mean. On the other hand, a low standard of
deviation is considered to be more consistent and concentrated around the mean.
One factor, for high results of standard deviation, is that the variables used are sensitive
instruments therefore leading to extreme changes in the annual value of the variable. For
example, from the data collected, GDP in Italy decreased from $23,175 to $18,683 which results
to a higher range between the minimum and maximum outliers thereby setting a higher standard
deviation. Net Trade has an exceptionally large standard deviation of 158.909 since it is being
measured as the difference between total exports and imports valued in billion U.S current
dollars. Italy again shows the high difference in change, annually, reporting a decrease in net
trade from -2.6472 to 11.9975. This, when transformed to the change in percentage of net trade,
equates to a staggering -209.92% and is an enormous decrease from the 67% achieved from 1995
to 1996 which will lead to a high value of standard deviation . Therefore, the data collected was
then transformed to a change in annual growth rate. The transformations led to a significant
decrease in standard deviation, although it is still considered high. Even though the results show
a high level of standard deviation, it can be accepted since the values of the variable collected
vary extremely over time and no effective methods could be used, other than transformation, to
lower standard deviation. Inflation records a standard deviation of 4.934. This is because the
difference between the minimum (-4.7%) and the maximum (45.3292%) is large. However, this
is expected since inflation is a sensitive instrument so countries suffering from hyperinflation
will set a higher maximum leading to an increase in standard deviation. Population growth has a
maximum growth of 3.7% and a minimum of -0.86%. The small difference in the maximum and
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minimum is because population is measured in terms of billions while population over 65 has a
much lower value. Therefore a substantial increase or decrease in the annual change of
population over 65 will have very minimal effects on the total population.
Table 1: Descriptive Statistics
3. Correlation Analysis
Correlation measures the statistical relationship of variables. This correlation analysis will
discuss what relationship variables hold with each other and with inequality. Figure 2 provides
some known relationships but does also make available interesting ones. For example, it is well
known that, an increase in unemployment will decrease GDP and this analysis shows that they
do hold a negative relation of -0.312934. This correlation seems weakly correlated but overall is
considered significant because there are many more factors that affect GDP per capita in an
economy. Alternatively, the correlation between Gini and the labour force with secondary
education, 0.011466, is very low to assume if there exists a strong relationship between the two.
However, analysing the relation variables hold with Gini shows interesting results. Past literature
studies have shown that direct income tax has a negative relationship with inequality, where an
increase in tax will lower the Gini. Figure 2 shows support for these past studies, by valuing the
relation between inflation and Gini to be 0.104190, showing the relationship to be positively
correlated. Also supporting past studies, to a certain extent, is the very weak negative relation
between tax and Gini, having a correlation coefficient of -0.064452.
The results of figure 2 show that there exists a low level of collinearity between Gini and the
independent variables, highest being inflation. This is positive since having high collinearity
increases the standard errors of their coefficients, and it may make those coefficients unstable
which would affect the performance of the control variables.
GDP GINI INFLATION LFSE LFTE TRADE POP TAX UNEMP
Mean 4.562 0.435 3.641 0.607 3.325 -0.609 1.008 0.0760 3.164
Median 5.331 -0.065 2.408 0.3250 2.815 5.155 0.980 0.050 0.000
Maximum 30.186 33.28 45.329 29.520 67.420 1170.010 3.700 52.790 150.910
Minimum -29.484 -27.09 -4.480 -19.180 -30.110 -1785.960 -0.860 -33.540 -30.430
Std. Dev. 9.863 6.838 4.934 4.126 7.275 158.909 0.866 6.885 19.0013
Skewness -0.258 0.4273 4.442 0.811 3.064 -3.627 0.238 0.3752 2.232
Kurtosis 2.920 6.334 27.592 16.575 32.864 56.923 2.631 14.419 13.682
Jarque-Bera 4.858 211.241 12192.38 3333.110 16574.370 52792.600 6.457 2335.795 2390.239
Probability 0.088 0.000 0.000 0.000 0.000 0.000 0.0396 0.000000 0.000
Sum 1952.677 186.350 1558.385 259.810 1423.030 -259.730 431.620 32.570 1354.390
Sum Sq. Dev. 41537.56 19965.06 10397.42 7270.792 22600.01 10782760 320.433 20241.570 154169.100
Observations 428 428 428 428 428 428 428 428 428
15
Table 2: Correlation Matrix
Part IV Methodology
A Panel Least Squares regression is applied to estimate the model of 21 countries over 21 years,
from 1992-2012. Using a cross-sectional panelled regression allows for both time and countries
to be used as an ID to observe changes in inequality and the possible effects that could arise.
Therefore, cross-sectional fixed effect is used to eliminate the constant variance of the countries
being analysed. Only countries in Europe were selected as this thesis discusses if countries in the
European Union, and who are part of the economic and monetary union (EMU), display a
significantly lower income inequality compared to countries outside the European Union.
This can be determined using the cross-section fixed effect, as the regression will interpret the
results in terms of dummy variables. The dummy variable will split the result in two, using the
variable “1” to represent countries that have a lower Gini coefficient than the average rate in
Europe therefore indicating low inequality. Conversely, using the dummy variable “0” will
represent countries with a higher income inequality than the average rate. The data of Gini Index
is used to value the dummy variables. The mean of Gini is 29.60468 and will be used to set the
dummy variable. Therefore, a country having an inequality over 29.6 will have a dummy
variable of 1 while a dummy variable of 0 is given to countries with lower inequality than 29.6.
Finland have achieved the lowest ever Gini Index, 19.7, while the United Kingdom acquired the
highest Gini Index in Europe, 38.7, over the past 21 years. However, the mean for Gini in table 1
is 0.435 since the descriptive statistic was inputted after the variables were transformed from its
original value.
To understand which variables need differencing, a unit root test should be applied to analyse if
variables are non-stationary over time. All the variables in this study needed first differencing in
order to overhaul the problem of omitted variables in this panel regression. GDP per capita
originally had a probability value of 0.8052 indicating that GDP is statistically insignificant to
Gini as it has a probability value higher than 0.05. Therefore, first differentiation under the
Levin, Lin & Chu Test is required to remove the factor of omitted variables.
GDP GINI INFLATION LFSE LFTE TRADE POP TAX UNEMP
GDP 1.000000
GINI -0.000419 1.000000
INFLATION 0.121829 0.104190 1.000000
LFSE 0.007336 0.011466 0.026629 1.000000
LFTE 0.020592 -0.051215 -0.032955 -0.384712 1.000000
TRADE 0.137426 -0.024440 0.193599 -0.008523 0.009113 1.000000
POP -0.078199 0.037387 0.225201 -0.020774 -0.036787 -0.017407 1.000000
TAX 0.094953 -0.064452 0.039555 0.082824 -0.073871 0.017952 -0.037476 1.000000
UNEMP -0.312934 0.066004 -0.025511 -0.002213 0.093742 -0.035001 0.044472 -0.185900 1.000000
16
Table 3: Unit Root Test (First Differencing)
The results in table 3 shows that first differencing, by the Levin, Lin & Chu Test, makes GDP
per capita more statistically significant as the probability value measured is 0.000.
GDP per capita was originally valued in current U.S dollars and was denoting higher values
compared to the other variables. It was also found that GDP per capita is highly skewed therefore
making the Log transformation ideal as it will produce a less skewed GDP per capita. It is then
transformed to the annual growth rate, in order for all variables to have equal measurements. The
equation used to transform GDP per capita is:
Log-GDP Growth = 100 * [Log(GDP(t)) – Log(GDP(t-1))]
, where “t” represents the current year and “t-1” represents the year before. All other variables are
transformed to the annual change in growth rate, except for inflation as it originally measures the
change in consumer price index (CPI). The equation used for this transformation is as follows,
“x” indicating all the variables excluding GDP per capita and inflation:
X Growth = 100 * [X(t)/X(t-1) – 1]
The panel regression used in this study is based in 21 countries and over 21 years, therefore there
should be 441 total observations recorded. However, table 4 shows the total panel of observation
to be 428. These few missing data were unable to be interpolated since there were no data
provided before the missing datum to estimate a mean. Nevertheless, the missing data will not
affect the result of the regression as it is a very small percentage of the total observations.
The model created by the panel regression equates to:
Gini = β₀ + β₁LogGDP + β₂INF + β₃POP + β₄LFTE + β₅LFSE +
β₆TAX + β₇UNEMP + β₈TRADE + ᶙi + Ԑ
Method Statistic Prob.** Cross-se
ctions
Obs
Null: Unit root (assumes common unit root process)
Levin, Lin & Chu t* -11.9748 0.0000 21 420
Null: Unit root (assumes individual unit root process)
Im, Pesaran and Shin W-stat -10.1030 0.0000 21 420
ADF - Fisher Chi-square 178.144 0.0000 21 420
PP - Fisher Chi-square 198.073 0.0000 21 441
17
Gini measures income inequality, LogGDP is the natural log of GDP per capita in terms of
growth, INF accounts for the consumer price index, POP is the percentage change in population
over the age of 65, LFTE and LFSE are labour force in tertiary education and labour force in
secondary education respectively and they show the percentage change in growth of these two
variables. TAX indicates the growth of direct tax, UNEMP indicates the growth of
unemployment compared to the total population and TRADE shows the growth of difference
between exports and imports as a balance of payment. β represents the coefficients for different
variables , ᶙi represents country fixed effects and Ԑ represents error.
Part V Results
The results for the model, measuring inequality, are examined in table 4. R-squared is recorded
to be 0.0346 which implies that the model runs a low goodness of fit. The Adjusted R-squared is
lower, -0.033107, than the R-squared as expected. Adjusted R-squared provides a more accurate
analysis since it runs a standard error of the regression in order to run a balanced estimator and
adjusts the sample size and the number of coefficients to its correct value.
The probability value of all the variables is high, other than inflation, meaning that they are not
significant to income inequality. However this does not mean that the effect of the independent
variable on inequality is low as it is possible for a variable to be insignificant and still have a
high effect on inequality. Conversely, it is the coefficient that measures the size effect of the
independent variable on the dependent variable. In table 4, inflation shows to have an interesting
relationship with income inequality. The probability value of inflation is low, 0.0344, indicating
a significant effect on income inequality since it is lower than the 5% confidence interval. The
coefficient of inflation is 0.185 showing that there is a strong positive effect between the two.
Although it is a low value to assume a strong effect, inflation is one of the many factors affecting
inequality therefore only having a small effect towards inequality as a whole. The relationship
between inflation and inequality can be concluded by stating they are significant and there exists
a strong positive relation between the two. This is interesting because past literature has
consistently discussed inflation to be positively related to inequality. Fahim A. Al-Marhubi
(2007) reached conclusions in his study that stated inflation and income inequality is positively
related and the results are robust. This supports our study that an increase in inflation will
increase income inequality.
Another factor that has been achieving consistent results in past literature is tax. However, the
measurement of tax in this study is only in terms of income tax. Grace Anyaegbu (2011) analysed
that inequality was lowered by 3 percentage points through income tax. However, government incentives
show a more significant effect by lowering inequality by 15 percentage points in the United States.
Therefore, this study supports the results of Anyaegbu (2011), in that tax is insignificant due to the high
probability value being greater than the confidence interval. Also the coefficient of tax is highly relatable
18
to previous studies. Income tax has a negative relation of 0.0623 with inequality, indicating that a 1%
increase in income tax leads to a0.0623% decrease in income inequality. This is, to some extent,
equivalent to the decrease of 3 percentage points on income inequality. To conclude, this study and past
studies support one another stating there is no significant effect between tax and inequality and there is
only a weak negative relationship between the two.
The other variables used in the regression do not hold a strong or significant relationship with inequality.
An argument for this could be that economists found contradicting results between the variable and
inequality. For example, Wood (1994) states that the introduction to globalization will lower income
inequality while Lee and Vivarelli (2004, and 2006b) used the same model, Heckscher–Ohlin
(HO) model, to contradict Wood’s theory. There lacks strong evidence for some of the variables
while the others examined are under assumptions in theory. This could lead to the possibility that
some of the variables produce inaccurate or irrelevant estimates.
Education does not seem to have consistent results and not much could be analysed in terms of
the effect it has on inequality. However, it could be concluded that both variables, LFTE and
LFSE, are not significant. The fact that there is a difference between the two coefficients and two
probability values raises an interesting debate. The coefficient for the labour force that has
tertiary education is -0.0646 compared to secondary education -0.0272. Also, LFTE has a more
significant effect since it has a lower probability value than LFSE. This analysis could possibly
interpret that completion of tertiary education will have a more positive impact on inequality
compared to secondary education.
Another study this thesis sets to examine is whether countries in the European Union have a
lower income inequality compared to countries outside the European Union. Instead of running a
separate regression for a Least Square Dummy Variable, a fixed country effect is applied to the
current one adjusted for dummy variables. The purpose of a fixed effect is that it essentially adds
independent time effects to for every unit correlated to the regression. Comparing fixed effect
coefficients to the coefficient of the regression will possibly interpret if countries in the European
Union generally have a lower inequality against countries outside. A dummy variable of 1 will
represent countries that are above the coefficient -0.227 hence indicating low inequality. On the
other hand, a dummy variable of 0 will be given to countries below the coefficient indicating
high inequality. Table 4 shows the value of all fixed effect coefficients to be above the
coefficient of the regression hence interpreting that all countries have a dummy variable of 1
indicating low inequality. However, fixed effect shows no consistent or significant pattern in
order to adjust dummy variables. Therefore, it could be concluded that there is no significant
relationship between low inequality and countries in the European Union. Perhaps a more
effective study would be analysing the effect of inequality in developed and developing countries
since past and present studies have showed growth to be a main indicator for inequality.
19
Table 4: Panel Cross-Sectional (Fixed Effects) Regression
Dependent Variable: GINI
Total panel (unbalanced) observations: 428
Variable
Coefficient Std.
Error
t-Statistic Prob.
C -0.227769 0.704331 -0.323383 0.7466
GDP 0.020455 0.037518 0.545214 0.5859
INFLATION 0.185083 0.087212 2.122216 0.0344
NET_TRADE -0.002004 0.002213 -0.905778 0.3656
POPULATION 0.047883 0.479942 0.099769 0.9206
LFTE -0.064666 0.052284 -1.236814 0.2169
LFSE -0.027212 0.093918 -0.289738 0.7722
TAX -0.062327 0.050579 -1.232275 0.2186
UNEMPLOYMENT 0.026134 0.019347 1.350816 0.1775
Fixed Effects (Cross)
_AUSTRIA--C -0.002331
_BELGIUM--C 0.008257
_CZR--C 0.000584
_DENMARK--C 0.012560
_ESTONIA--C -0.007872
_FINLAND--C 0.007215
_FRANCE--C 0.004978
_GERMANY--C 0.006143
_GREECE--C 0.002437
_HUNGARY--C -0.004359
_IRELAND--C -0.003182
_ITALY--C 0.001366
_LUXEMBOURG--C -0.000664
_NETHERLANDS--C -0.009741
_POLAND--C -0.001394
_PORTUGAL--C -0.009018
_SLOVENIA--C 0.001913
_SPAIN--C -0.001178
_SWEDEN--C 0.008674
_SWITZERLAND--C -0.011113
_UK--C -0.004255
Effects Specification
Cross-section fixed (dummy variables)
R-squared 0.034638 Mean dependent var 0.435397
Adjusted R-squared -0.033107 S.D. dependent var 6.837878
S.E. of regression 6.950148 Akaike info criterion 6.780755
Sum squared resid 19273.52 Schwarz criterion 7.055789
Log likelihood -1422.082 Hannan-Quinn criter. 6.889378
F-statistic 0.511296 Durbin-Watson stat 2.811819
Prob(F-statistic) 0.983073
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Part VI Conclusion
The main objective of this thesis was to find a relationship between the economic elements of
income inequality and inequality. Income inequality is a main indicator for economic growth,
therefore it is ideal to find the characteristics affecting inequality in order to increase economic
growth.
Data was collected from 21 different countries in Europe over 21 years. Regression was
estimated in order to analyse the significance and the size effect of the independent variables
against income inequality.
Certain limitations in this thesis restrict the fact for regression to provide a better analysis and
higher level of significance. For example, a simple Panel Least Square regression lacks the
advanced program and technique to measure accurate and significant values for the effect of
certain variables on inequality. Also, a variable could be lagged in order to achieve a more
accurate result. For example, a change in the inflation rate today will not immediately affect the
change in Consumer Price Index. It will take a certain amount of time for CPI to be adjusted to
the inflation rate, therefore lagging the variable would be ideal in order to set the outcome within
the time range of the original change. Assumptions are considered barriers to running a
regression as it only portrays the model and not the real economy. Meschi (2007) relaxes the
assumption of identical technologies allowing developed countries to transfer their advanced
technologies to developing countries. Relaxing this assumption, allows Meschi to examine the
increase in income inequality due to factors that was not available before the assumption was
dropped. Logically, lack of data provided will make the regression less accurate hence regression
can be improved by firms and databases making more data available to the public. This could
have been one of the cases for the regression ran in this study. For example, limited Gini Index
data is provided by the World Data Bank, going back to only 1992 and there were a few
significant data missing. Increasing the database will allow more accurate tests to be run and
most likely a better regression analysis, measuring to what extent independent variables effect
inequality. Although not used in the regression of this thesis, running a fixed time effect will take
into account economies suffering from global shocks. Therefore, a fixed time effect will increase
the accuracy of the regression. Adding all these techniques on the regression analysis will
improve the results and possibly show a stronger relationship and higher significant level
between income inequality and the dependent variable.
To conclude this thesis, a regression analysis was undertaken to see how dependent variables
affect income inequality and if the effects are consistent with previous studies. The regression
analysis for this thesis shows inflation and tax to be consistently and significantly related to past
studies. However, the other variables were found to be irrelevant due to not having a significant
effect nor a strong relationship with inequality. This could occur if past studies are tested without
sufficient evidence or if there are too many assumptions stressed on inequality. Therefore
applying lag or relaxing assumptions would possibly improve the results of the regression.
21
Perhaps during future studies, more data will be made available and new techniques will be
established to provide a strong and significant link between income inequality and the variables
affecting it.
22
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