2011年-世界发展银行全球_Water_and_Sanitation_to_Reduce_Child_Mortality___The_Impact_and_Cost_of_Water_and_Sanitation_Infrastructure_39页_1mb

Summary: Water and Sanitation to Reduce Child Mortality

Core Content

This paper investigates the impact and cost-effectiveness of water and sanitation infrastructure in reducing child mortality, focusing on the Millennium Development Goal (MDG) 4, which aims to reduce child mortality by two-thirds between 1990 and 2015. The authors use household survey data from the Demographic and Health Surveys (DHS) to estimate the mortality impact of improved water and sanitation access.

Main Findings

• Mortality Reduction: Improved water and sanitation infrastructure significantly reduces child mortality. On average, access to "basic" improved water and sanitation technology reduces child mortality by 8 deaths per 1,000 children born, while access to high-end technologies such as private water connections and flush toilets leads to a 25 deaths per 1,000 children born reduction.

• Contribution to MDG 4: The estimated reduction in child mortality due to improved water and sanitation could account for 40% of the gap between current child mortality rates and the 2015 MDG target. Basic infrastructure could reduce the gap by about 13%, while high-end technologies could reduce it by 41%.

• Cost-Effectiveness: The average cost per life-year saved for water and sanitation infrastructure is between 65% and 80% of GDP per capita in developing countries. In Sub-Saharan Africa, the average cost per life-year saved is around US$1,000, while in other regions it is higher (around US$3,000). Despite this, the cost per life-year saved relative to income per capita is similar across regions, indicating that these investments are highly cost-effective.

• Humanitarian Impact: Full household coverage with improved water and sanitation infrastructure in the developing world could save about 2.2 million child lives per year. In the sample of 38 countries, this intervention has the potential to save 1.3 million child lives annually.

Key Information

• The study focuses on 38 developing countries with recent DHS data (2000–2006).
• It estimates the health impact of water and sanitation using a logistic regression model that links improved access to child mortality outcomes.
• The model predicts counterfactual mortality rates under various infrastructure improvement scenarios.
• The paper classifies water and sanitation infrastructure into three broad categories based on the WHO/UNICEF Joint Monitoring Program (JMP) ladder, with some refinements to better capture the differences in technology and health impact.
• Improved sanitation is defined as having access to flush toilets connected to a septic tank or sewage system, while improved latrines include private or shared facilities that are more hygienic than traditional ones.
• The analysis shows that higher-end technologies are more costly but also more effective in reducing mortality, leading to similar cost per life-year saved as basic technologies due to their longer durability and greater health benefits.

Methodology

1. Data and Variables: The study uses DHS data, which provides nationally representative household surveys. The authors construct a binary mortality variable indicating whether a child aged 0–48 months died within the 12 months prior to the survey.
2. Model Specification: A logistic regression model is used to estimate the relationship between water and sanitation infrastructure and child mortality.
3. Scenarios and Predictions: The authors simulate different scenarios of infrastructure improvement and estimate the potential reduction in child mortality for each.
4. Cost Estimation: The cost of infrastructure investment is combined with the mortality reduction estimates to calculate the cost per life-year saved for each country.

Policy Implications

• The results suggest that investment in water and sanitation is a highly cost-effective policy tool for reducing child mortality, even when considering only mortality benefits.
• Additional benefits such as reduced morbidity, time savings, and environmental improvements further enhance the benefit-cost ratio.
• The study highlights the urgent need for improved water and sanitation infrastructure, particularly in Sub-Saharan Africa, where progress has been slow and child mortality remains high.
• It underscores the importance of targeting high-impact technologies to maximize the health and economic benefits of such investments.

Conclusion

The paper provides strong evidence that improving water and sanitation access can significantly reduce child mortality and is a cost-effective intervention. It emphasizes the need for accelerated investment in these areas to meet the MDG 4 targets and improve public health outcomes globally.