🗺️ A New Proxy for State Reach
Travel time to national and regional capitals is used as a proxy for local state capacity. Comprehensive panel data were constructed to capture how changes in physical access to state centers shaped development across Africa.
📊 How the Measure Was Mapped (1966–2016)
- A yearly 5 × 5 km grid covering African territory was created for 1966–2016.
- Time-varying data on roads and administrative boundaries were used to compute travel times to both national and regional capitals for every grid cell.
🔎 What Outcomes Were Tested
- Local education provision
- Infant mortality rates
- Nightlight emissions (as a proxy for economic activity)
📈 Key Findings
- Within the same location, decreases in travel times to capitals are robustly associated with better development outcomes.
- Shorter travel times correlate with improved education provision, lower infant mortality rates, and higher nightlight emissions.
⚖️ Why This Matters
- Provides a fine-grained, time-varying measure of state reach that advances measurement of state capacity.
- Connects changes in physical access to state centers with concrete improvements in human welfare, offering a clearer link between state infrastructure, administrative reach, and development outcomes.
