2016年-PIIE彼得森国际经济研究所_The_Future_of_Worldwide_Income_Distribution_44页_1mb

The Future of Worldwide Income Distribution

Core Content

This working paper by Tomás Hellebrandt and Paolo Mauro provides a projection of global income distribution for the year 2035, based on population and GDP growth forecasts combined with household income survey data from over 100 countries. The paper highlights the long-term implications of these changes for consumption patterns and policy challenges.

Main Viewpoints

• Global Inequality is Declining: The Gini coefficient of global income inequality has decreased from 69 in 2003 to 65 in 2013 and is projected to fall further to 61 in 2035.
• Emerging Markets Drive the Decline: The decline in global inequality is primarily attributed to the rapid economic growth in emerging-market economies, especially in Sub-Saharan Africa and India.
• Consumption Patterns Will Shift: As more people move into higher income brackets, the composition of consumption will change. A convex relationship between per capita consumption and the share of transportation in total consumption is identified, suggesting a faster rise in transportation spending than previously anticipated based on GDP growth.
• Scenario Analysis: The paper explores different scenarios, including a "reversion to mean" scenario and an "optimistic scenario" for India and China, to assess the potential range of outcomes for global inequality.

Key Information

Baseline Projections

• Global GDP in 2035: Projected to reach $210.0 trillion, representing an average annual growth rate of 3.5% from 2013 to 2035.
• Global Population in 2035: Estimated at 8.56 billion, a 21.9% increase from 2013.
• Per Capita GDP in 2035: Expected to be around $24,500, with an average real per capita growth rate of 2.6% annually.
• Income Brackets:
  • People earning between $1,144 and $3,252 (PPP terms, 2013 prices) will increase by about 500 million.
  • Those earning between $3,252 and $8,874 will rise by almost 1 billion.
  • Individuals earning more than $8,874 will increase by 1.2 billion.
• Major Gainers:
  • Sub-Saharan Africa and India will see the largest increases in people moving into middle and higher income brackets.
  • China and advanced economies will be the main contributors to the increase in high-income individuals.

Methodology

• The analysis uses household survey data from the Luxembourg Income Study (LIS) and World Bank data to estimate global income distribution.
• It assumes no change in within-country income inequality over the next two decades, based on the late 2000s survey data.
• The paper uses PPP conversion factors to ensure accurate purchasing power comparisons across countries.
• A simple autoregressive model is used to project GDP growth for countries not covered by OECD or Consensus Forecasts.

Population Growth Trends

• Developing and Emerging Economies: Will account for most of the global population growth, reaching 8.6 billion by 2035.
• Sub-Saharan Africa: Will experience the largest population increase, from 0.9 billion to nearly 1.6 billion.
• China and Eastern Europe/Central Asia: Will see limited or no population growth, respectively.
• Advanced Economies: Will experience slow population growth, with net gains mainly in the United States, Australia, and Canada.

GDP Growth Trends

• Developing and Emerging Economies: Projected to grow faster (3.8% annually) than advanced economies (1.8%).
• China and India: Expected to have the highest per capita GDP growth rates (4.4% and 4.8%, respectively).
• Sub-Saharan Africa: Projected to grow at 3.5% annually.
• Total GDP Growth: Sub-Saharan Africa and India will see the fastest total GDP growth due to their high population and income growth rates.

Alternative Scenarios

• Reversion to Mean Scenario: Global inequality would decline more slowly, with a Gini coefficient of 64 in 2035.
• Optimistic Scenario for India and China: If both maintain rapid growth (7% annually), the global Gini coefficient would fall to 63, but with India reducing inequality and China increasing it due to its already relatively high income levels.

Policy Implications

• The rise in consumption, especially in transportation, will create new opportunities for companies and investors.
• However, it will also raise challenges related to scarce natural resources, climate change, and the need for infrastructure development.
• The paper emphasizes the importance of global income distribution in shaping consumption patterns and policy decisions.

Conclusion

The paper underscores the significant transformation in global income distribution over the next two decades, driven by the rapid growth of emerging-market economies and the corresponding increase in the global consumer base. The use of household survey data and PPP conversion factors enhances the accuracy of the projections, while the exploration of alternative scenarios provides a nuanced understanding of the potential impacts of different growth trajectories.