世界银行-公共工程项目是否具有持续影响？：LMIC实验研究综述（英）-2023.6-42页_978kb

Summary of "Do Public Works Programs Have Sustained Impacts?"

Overview

This review analyzes experimental evidence on the short-term and medium-term impacts of public works programs in low- and middle-income countries (LMICs). It examines employment, earnings, consumption, savings, assets, women's empowerment, and psychological well-being, drawing from 11 randomized controlled trials across nine countries.

Key Findings

• Employment and Earnings: Public works programs significantly increase employment and earnings during the program but these effects largely fade in the medium run. The short-term impact averages 29.3 percentage points on employment and USD 51.3 monthly earnings, but forgone earnings reduce net gains, questioning cost-effectiveness.
• Food Consumption: Little evidence shows improvements in household food expenditure, with an average medium-run effect of USD 3.7, which is insignificant.
• Savings and Assets: Positive effects persist in some cases, with savings increasing by 5.9 percentage points and assets by 0.21 standard deviations, potentially sustaining impacts through investments in self-employment.
• Women's Empowerment and Well-being: Programs improve women's income in some instances, but effects on empowerment and psychological well-being are inconsistent and not systematically significant.

Policy Lessons and Future Directions

• Public works programs excel in short-term employment and earnings but lack sustained medium-term impacts on key outcomes. Cost-effectiveness is questionable due to forgone earnings.
• Recommendations include better data collection, optimizing program design (e.g., wages, duration), exploring "public works plus" interventions to support transitions to steady employment, and rigorous cost-effectiveness analysis. Further research is needed in diverse regions and on broader measures of well-being.