2015年-世界发展银行全球_The_Cost_of_Road_Infrastructure_in_Low_and_Middle_Income_Countries_57页_751kb

The Cost of Road Infrastructure in Low and Middle Income Countries

Core Content

This paper investigates the unit costs of road construction and maintenance in low and middle income countries, focusing on the factors that influence these costs, particularly conflict and corruption. The study aims to provide quantitative evidence on cost variations and their implications for economic development and policy-making.

Main Findings

• Large Dispersion in Unit Costs: There is significant variation in unit costs for comparable road work activities across countries. For example, the cost of an asphalt overlay between 40 and 59 mm differs by a factor of three to four.

• Conflict Increases Costs: After controlling for environmental factors such as terrain ruggedness and market access, unit costs in conflict countries are 30% higher on average. This effect is robust across different measures of conflict and political instability.

• Corruption Raises Costs: Countries with higher levels of corruption have higher unit costs. A move from the 75th to the 25th percentile of corruption is associated with a 6.8% reduction in unit costs. Countries with corruption levels above the median in the sample have 15% higher costs.

• Robustness to Controls: The effects of conflict and corruption on unit costs remain significant even after controlling for a country's public investment capacity and business environment.

Key Drivers of Cost Variation

• Environmental Factors: Terrain ruggedness and proximity to markets are important cost drivers. These factors influence the efficiency of construction and the scale of returns in road projects.

• Conflict-Related Risks: Conflict increases costs due to:

  • Security risks and the need for monitoring.
  • Disruptions to transport networks leading to supply chain issues.
  • Reduced government capacity and increased risk premiums for firms.

• Corruption in the Sector:

  • Government-level corruption: Officials may receive bribes to select contracts or process documents, leading to inefficiencies and higher costs.
  • Firm-level corruption: Contractors may inflate costs and extract bribes, which reduces the likelihood of the project being selected due to lower net present value or return.
  • Material misrepresentation: Companies may use fewer or lower-quality materials, affecting the cost and efficiency of road projects.

Data and Methodology

• Data Source: The study uses the Roads Cost Knowledge System (ROCKS), a database of 3,322 unit costs from 99 low and middle income countries, compiled by the World Bank.

• Unit Cost Categories:

  • Road development works and road preservation works are classified.
  • Unit costs are defined per square meter or km.
  • Costs are deflated to the year 2000 using the domestic consumer price index and converted to US$ using the 2000 exchange rate.

• Cost Types:

  • Estimated costs (44% of entries).
  • Contracted costs (27% of entries).
  • Actual costs (29% of entries).

• Methodological Approach:

  • The study uses fixed effects at the work activity level to control for systematic differences in costs.
  • It explores the relationship between public investment management capacity and unit costs.

Additional Considerations

• Limitations:

  • The paper does not address economic feasibility of projects.
  • It does not have information on projects that would have occurred in the absence of conflict.
  • The simple model does not account for all factors, such as market structure, tender procedures, and hold-up problems.

• Policy Implications:

  • Countries with high unit costs due to conflict or corruption should prioritize reducing population dispersion or improving public investment management.
  • Understanding the cost drivers is crucial for developing effective infrastructure policies and connectivity strategies in low and middle income countries.

Conclusion

The paper contributes to the growing body of research on the economic implications of transport infrastructure, emphasizing the cost side. It highlights that conflict and corruption significantly affect the unit costs of road infrastructure, even after controlling for other variables. These findings are important for governments and donors aiming to improve infrastructure in developing countries, as they underscore the need for addressing institutional and environmental challenges in the sector.

References and Supporting Literature

• Benamghar and Ilimi (2011): Highlight the risks associated with road construction in conflict settings.
• Olken (2007): Shows that corruption leads to missing expenditures in infrastructure projects.
• Burgess et al. (2015): Finds higher expenditures in districts with similar ethnicity to the president.
• Transparency International (2011): Reports that public works contracts are the sector with the highest propensity to pay bribes.
• World Bank (2006): Provides the foundational data for the study.

Summary of Cost Types and Work Activities

• Most Expensive Development Work: New six-lane expressway, followed by four-lane expressway.
• Most Expensive Preservation Work: Concrete pavement restoration, followed by strengthening.

Notes on Data Collection and Processing

• Excluded Duplicates: 31 contracts with duplicate entries were removed.
• Currency Adjustments: Costs were adjusted to US$ using the official exchange rate and the World Development Indicators 2012 consumer price index.
• Time Window: The study limited the time window to avoid conflating cost differences with changes in input prices.