The World Distribution of Income And Its Inequality, 1970–2009

This paper provides a full decomposition of world inequality, as measured by the Gini coefficient, in the period 1970–2009. In particular, using the Analysis of Gini (ANOGI), the paper describes the evolution of between inequality, within inequality, and the impact of overlapping on both factors. While there is evidence that between inequality in the last decade significantly declined due to the rapid Chinese growth, within inequality and overlapping went in the opposite direction. Furthermore, with the exception of some Asian countries, the rest of the world has not moved significantly. As a result, world inequality remains high by any standard.     

我国城镇居民收入差距演变及"十一五"趋势分析

笔者通过综合使用基尼系数、分组收入份额和分组人均可支配收入实际增长率等指标,多角度定量分析我国城镇居民收入差距的演变过程,认为1985年以来,城镇居民收入差距一直在不断扩大;收入差距加速扩大的局面在2006年开始出现扭转势头。立足于宏观经济背景,作者预测"十一五"期间分组收入份额差距将继续缩小,基尼系数将会降低,有望实现"十一五"规划和十七大提出的"逐步扭转收入分配差距扩大趋势"的目标。     

中国农村地区间居民收入差距及构成变化:1995—2008年——基于基尼系数的分解

本文采用分省的面板数据对农村地区间基尼系数分解结果表明,1995—2008年,中国农村地区间收入差距总体上仍然呈现上升趋势,基尼系数上升了0.0639,但增幅出现明显减弱趋势。基尼系数变化及农村居民工资性收入对基尼系数的贡献变化显示出与经济发展阶段变化一致的含义;结构性效应已不再是农村地区间收入差异的唯一构成来源,收入集中效应对基尼系数起了明显的增加作用,工资性收入的集中效应超过了其他收入来源。这些构成来源的变化蕴含着中国面临调节地区间农村收入差距的政策机遇。     

A matrix approach to the Gini index decomposition by subgroup and by income source

The literature offers two main ways of decomposing the Gini index: decomposition by population subgroup and by income source. This article proposes merging the two decomposition dimensions by suggesting a matrix formula for the Gini index which permits the simultaneous decomposition by subgroup and by income source. Using this multi‐decomposition, one can investigate the role of the interaction between the subgroup and the source components in determining the overall inequality. We apply the methodology to sample data on Italian household incomes collected in 2008.     

城乡内部引起收入差距主要因素的对比分析——以山东省为例

利用源自CHNS的山东省数据,从收入来源的角度,对城乡内部各自的基尼系数进行分解,通过对比分析分项收入集中率,探究引起城镇和乡村各自内部收入差距的主要因素。得出结论:就经营性收入和工资性收入对收入差距的贡献率来说,城镇明显高于农村;就退休收入和其他收入对收入差距的贡献率来说,农村明显高于城镇;而在转移性收入对收入差距的贡献率方面,两者没有明显差异。     

Industrialization and spatial income inequality in rural China, 1986-921

Rural industrialization has been a dominant factor responsible for China's rapid economic growth over the last 18 years, but it has been accompanied by increased inter-regional income inequality. Using the most recent rural income data and two alternative Gini coefficient decomposition methods, this study finds that income inequality, especially inter-regional income inequality increased significantly in the period 1986-92. More than half of national income inequality was due to its inter-provincial component, and three quarters of inter-provincial inequality was due to its inter-zonal component. Uneven development of township and village enterprises has been a major cause of increased regional income inequality.     

A Note on α‐Gini Measures

This note provides a characterization of α‐Gini inequality measures. These measures generalize the standard Gini index by including one sensitivity parameter α, which captures different value judgments. The α‐Gini measures are shown to be weakly decomposable and unit consistent. Weak decomposition provides within‐group and between‐group inequalities. Unit consistency keeps unchanged the ranking of two income distributions when the income units vary. It is shown that the α‐Gini measures are relevant with either “leftist” or“rightist” views.     

A Gini decomposition analysis of inequality in the Czech and Slovak Republics during the transition1

Disposable income inequality, as measured by the Gini coefficient and using the Family Budget Survey data, increased very little, and by a similar amount, from 1989 to 1993 in the Czech Republic and Slovakia. This surprising result is examined with an analysis of changes in the channels of redistribution and Gini decomposition. We find that the sizeable increase in overall inequality due to changes in the wage earnings component is mitigated by changes in the tax and transfer components in both republics. As for the relative effects of government policies, changes in the transfer component contributed more than changes in the tax component to lowering the growth of inequality in the Czech Republic, while the reverse was true for Slovakia.     

Measuring the Impact of Various Income Sources on the Link between Inequality and Development: Implications for the Kuznets Curve

To understand the link between inequality and development, a decomposition of the Gini index by income sources is used that emphasizes the role of three components measuring the impact of the shares of the sources, the degree to which they are unequally distributed, and their correlation with total income. Such a breakdown explains why the rising section of the Kuznets curve is mainly the consequence of the increasing share of wages while its declining section reflects the decreasing share of entrepreneurial income and the negative correlation between transfers and total income. The data sources were provided by the International Labour Office.     

Decomposition of the Gini Index by Sources of Income

The Gini concentration coefficient is considered to be the best synthetic inequality measure and is widely used in economic research. In this paper, we present its decomposition by factor components with an application to income distributions in Poland. Income inequality measures proposed by Gini, Zenga and Bonferroni are calculated for different socio-economic groups based on their exclusive or primary source of maintenance. For theoretical income distribution, the Dagum type-I model was used. The basis for the calculations was the individual data coming from the Household Budgets Survey conducted quarterly by the Polish Central Statistical Office. Using the decomposition of inequality by source, we were able to examine how changes in particular income components affected overall inequality.      

A tale of two Ginis in the US, 1921–2012

Following a methodology by Jantzen and Volpert (2012), we use IRS Adjusted Gross Income data for the US (1921–2012) to estimate two Gini indices representing inequality at the bottom and the top of the income distribution, and to calculate the overall Gini as a function of the parameters underlying the two indices. A steady increase in the overall Gini since the Second World War actually hides two different periods of distributional changes. First, the increase in inequality from the mid 1940s to the late 1970s is driven by rising inequality at the bottom of the income distribution that more than offsets a decrease in inequality at the top. The implication is that middle-income earners gained relative to high-incomes, and especially relative to low-income earners. Second, the rise in the Gini after 1981 is driven by rising inequality at the top. Third, top-driven inequality follows a U-shaped trajectory consistent with Piketty and Saez (2003, 2006). Fourth, the welfare effects of the different distributional changes behind increasing inequality can be evaluated in light of the Lorenz-dominance criterion by Atkinson (1970): we argue that the rise in inequality since 1981 is much more likely to be associated with a social welfare loss net of compensating growth.     

The limitations of negative incomes in the Gini coefficient decomposition by source

Lerman and Yitzhaki (1985) developed a decomposition of the Gini coefficient by income source that has been extensively used in the literature. This method has strong limitations in the presence of negative incomes, which were not discussed by the original authors and have been widely overlooked in successive studies. Through theoretical argumentation and practical examples, this article shows that, when using negative incomes, (1) the original decomposition formulae become inappropriate, (2) the marginal effects analysis may yield erroneous results and (3) the Pigou–Dalton ‘principle of transfers’ is not always met. This has critical implications for policy development, given that strategies based upon incorrect analyses could actually result in undesired greater income inequalities. The Gini source decomposition should be carefully applied by researchers and policymakers, especially in rural developing areas, where negative incomes are common due to financial losses from agricultural activities.     

How large is income inequality in China: assessment on different estimates of Gini coefficient

The rising income inequality in China has attracted social attentions, especially since SWUFE published the unbelievably high Gini coefficient in December 2012. In order to answer the question how large income inequality in current China is, this paper compares existing different Gini coefficients estimated from four different household surveys, which are the NBS household survey, the CHIP survey, the CHFS of SWUFE, and the CFPS of Peking University, and then assesses these household surveys themselves. The relevant evidences indicate that the national Gini coefficient in current China is between 0.47~0.52. The sampling defects of the CHFS are significantly major and that the national Gini coefficient of 0.61 published by SWUFE is seriously overestimated.     

Calculation and decomposition of income inequality in low- and middle-income countries: a survey data analysis

This article estimates income inequality in a sample of four low- and middle-income (LMI) countries namely; Albania, Nepal, Tajikistan and Tanzania using the household survey data – Nepal Living Standard Measurement Survey Second. First, we estimate the income generation function for each country and calculate the income inequality using Gini index (GI). Second, we decompose the income Gini into the determinants of income generation functions. Based on the decomposition result, socio-economic factors are the most important determinants of income inequality followed by geographic factors. Demographic factors have the least effect on income inequality in all four countries. Third, we propose a new method to quantify the effect of change in each covariate of income generation function on income Gini. That allows us to quantify the effects of change in specific policy such as increase in investment in schooling or public health to specific group of the population in society on income inequality. A carefully chosen, integrated policy can significantly reduce inequality in all four countries under study.     

中国城乡收入差距 影响因素实证分析——基于收入来源视角

中国城乡收入差距在1978～2010年总体呈上升趋势,收入来源分解显示工资性收入对城乡收入差距的贡献度最高,经营性收入和转移性收入的贡献度呈现此消彼长的趋势。计量模型显示总体受教育水平的提高导致工资性收入差距缩小,但城乡教育发展不平衡使经营性收入差距扩大,促进城市化进程不会缩短工资性收入差距,城乡金融发展差异的扩大进一步扩大了经营性和转移性收入差距。缩小城乡收入差距的主要措施包括提高教育水平,实现城乡教育公平、城乡金融均衡发展和均衡城市化进程。     

二元经济中城乡混合基尼系数的计算与分解

关于基尼系数计算方法的文献已经十分丰富,但专门计算城乡混合基尼系数的理论方法,却一直没有得到很好的解决,这导致全国收入分配长期变化方面的某些研究难以深入。本文建立了城乡混合基尼系数的新算法,并给出新的分解形式,同时还提出并论证了度量城乡差距的新指标。该分解形式具有明确的经济含义和理论意义,并且不依赖于“城乡收入分布不重叠”的假定。利用这一分解形式的经济含义,我们分析了几个重要理论问题。最后,应用新算法计算并分解了中国个别年份的城乡混合基尼系数,以检验新算法的有效性。     

中国行业收入差距的实证分析

本文运用扩展的基尼系数进行实证分析表明,中国行业之间收入差距的基尼系数不断扩大,国有单位行业之间的收入差距基本上与全国行业之间收入差距保持一致,城镇集体单位行业之间收入差距的基尼系数变化不大,其他单位①行业之间收入差距不仅初始值比较高,而且扩大得比较快。造成上述结果的原因,一方面来自市场机制的作用以及私有化所带来的分配不均,另一方面来自国有部门行业之间收入差距扩大的影响及其国有部门行业的垄断性质。     

Report of China Household Income Disparity

Based on China Household Finance Survey (CHFS) data, China’s Gini Coefficient stood at 0.61 in 2010, above the global average of 0.44, according to the World Bank. The high Gini Coefficient represents a large income disparity of the country. It is understandable that a high Gini is common in fast-growing economies and can be reduced through government’s transfer payments given the experience of OECD countries. This paper illustrates the breakdown of China’s Gini, regional, rural and urban differences in household income. Specifically, it is found that poor health, insufficient social welfare and low education level are the main reasons for poverty of rural households. This paper also provides solutions to reduce the Gini coefficient. In the short term, China government can invest more on social insurance and implement large-scale transfer payments. The figure shows that China government has sufficient financial sources to strengthen secondary distribution to subsidize the low-income group. In the long term, government can increase overall educational level and reduce the opportunity inequality to narrow the income gap.     

影响我国农村居民收入差距的主要因素:从收入构成角度的分解分析

This paper attempts to explore the causes behind the change of the inequality in China rural areas at the very beginning of this century by decomposing the inequality of the total per capita income into the contributions from different income components. Furthermore, we develop the decomposition method of Gini coefficients from the income components and use it not only in the static analysis but also in comparative static analysis. Namely it can be used to explore the change of the overall inequality by decomposing the change of Gini Coefficient from income components. The empirical results show that the wage from local employment, the income from agricultural household business and the incomes from non-agricultural household business are the three income components that made the largest contributions to the inequality of the total per capita income. The total contribution to the overall inequality of non-agricultural incomes was much more than that of agricultural incomes. The incomes from agricultural household business, the incomes from non-agricultural household business and the wages from migration made the positive impact on the increase of the overall inequality. The incomes donated by relatives and friends made the most important negative impact on the increase of the overall inequality.     

中国省际城乡收入差距的来源贡献度分析

中国各省市城乡收入差距在1997～2009年总体呈上升趋势,经济欠发达省市较沿海省市城乡收入差距问题更严重。收入差距来源分解结果显示:工资性收入差距对城乡收入差距的贡献度最高,经营性收入和转移性收入差距的贡献度呈现此消彼长的趋势,财产性收入差距影响微乎其微。缩小城乡收入差距的主要措施是提高教育水平的同时,保证实现城乡教育公平、城乡公共服务均等化和有序稳定推进城市化进程。