2004年-世界发展银行全球_The_Effects_of_Infrastructure____________Development_on_Growth_and_Income_Distribution_43页_723kb

Summary of "The Effects of Infrastructure Development on Growth and Income Distribution"

Core Content

This paper examines the impact of infrastructure development on economic growth and income distribution using a large panel dataset covering 121 countries from 1960 to 2000. The study focuses on both the quantity and quality of infrastructure, employing a variety of econometric techniques to address potential endogeneity issues. The key findings suggest that infrastructure development has a positive effect on growth and a reduction in income inequality.

Main Viewpoints

• Infrastructure and Growth:

  • Infrastructure accumulation, particularly in transport, power, and telecommunications, positively affects GDP growth.
  • The marginal productivity of infrastructure assets is found to be significantly higher than that of non-infrastructure capital.
  • The study suggests that the slowdown in infrastructure development in Latin America contributed to the income per capita gap with East Asia during the 1980s and 1990s.

• Infrastructure and Income Inequality:

  • Infrastructure development reduces income inequality, especially when it improves access for low-income households.
  • Better infrastructure provides the poor with access to productive opportunities, reduces transaction and production costs, and increases the value of their assets.
  • Access to water and sanitation has a direct and significant impact on child mortality and, by extension, on income and welfare.

• Private Participation and Distribution:

  • Private participation in infrastructure may have mixed effects on distribution, depending on how reforms are designed.
  • It can lead to job creation and growth, but may also result in reduced access for the poor if not managed properly.
  • If used effectively, private participation can contribute to a more equitable income distribution.

Key Information

• The study uses GMM estimators with both internal and external instruments to account for endogeneity.
• Synthetic indices are constructed using principal component analysis to summarize infrastructure quantity and quality across multiple sectors.
• The aggregate index of infrastructure stocks includes:
  • Telecommunications: number of main telephone lines per 1,000 workers.
  • Power: electricity generating capacity per 1,000 workers.
  • Transport: total road length per square kilometer of land area.
• The aggregate index of infrastructure quality includes:
  • Telecommunications: waiting time for telephone main lines.
  • Power: percentage of transmission and distribution losses.
  • Transport: share of paved roads in total roads.
• The synthetic indices are highly correlated, with the infrastructure quantity index capturing 81% of the variance and the quality index capturing 73%.
• The correlation between the two synthetic indices is 0.74, indicating they share substantial common information.
• The study also considers the distributive impact of infrastructure, particularly in the context of private participation and its effects on employment and affordability for the poor.

Empirical Strategy

• The paper uses a panel data set of 121 countries over 1960–2000.
• The data is averaged over five-year periods to smooth out short-term fluctuations.
• The econometric model is defined as a dynamic equation for GDP growth and inequality, where the dependent variable is either GDP growth or an inequality measure.
• The model includes:
  • A lagged dependent variable.
  • A set of standard growth and inequality determinants.
  • Infrastructure quantity and quality indicators.
• The paper addresses endogeneity by using GMM-difference and system estimators, which combine first-differences and levels regressions.
• The moment conditions used in the estimation are based on the assumption that lagged values of the regressors are uncorrelated with the error term.

Conclusion

• The study finds that infrastructure development is causally linked to both economic growth and reduced income inequality.
• It emphasizes the importance of infrastructure quality and access for the poor, suggesting that effective infrastructure policies can be instrumental in poverty reduction.
• The results are robust across different specifications and highlight the economic significance of infrastructure in development and inequality reduction, especially in Latin America.