Tracking Bihar's Economic Growth Through Night-Time Light

Using Night-time light to Track Bihar’s economic growth

Fundamental Idea

Night-time light (NTL) data uses satellite images of illumination to measure human activity after dark. Economists consider it a reliable proxy for economic growth, as more light indicates rising urbanisation, industrial activity, better infrastructure, and household prosperity. This method is particularly useful in regions where conventional data collection is weak or delayed.

Study Findings for Bihar

Top Growth Districts: Patna, Vaishali, Muzaffarpur, Gaya, and Begusarai showed the fastest economic expansion.
Emerging Districts: Arwal, Jehanabad, Jamui, Banka, and Madhubani recorded sharp improvements in NTL, reflecting rising activity.
Sectoral Linkages: Growth was most visible in construction, retail, agriculture, animal husbandry, and small enterprises.

Changes in Illumination

Patna: Lighted area rose from 409 sq km in 2017 to 485 sq km in 2023.
Muzaffarpur: Expanded from 88 sq km to 309 sq km.
Vaishali: Increased from 50 sq km to 287 sq km.
Arwal: Jumped tenfold from 4.5 sq km to 50 sq km.
Jehanabad: Expanded from 14 sq km to 152 sq km.

Implications

Alternative Growth Measure: Night-time light provides quick, cost-effective insights into regional development.
Employment Linkages: Patna saw 51% of jobs coming from IT, e-commerce, and healthcare startups, while Muzaffarpur and Gaya had higher concentration in small enterprises.
Policy Use: Helps the government identify underdeveloped but fast-emerging corridors for targeted infrastructure, skills, and health services.

FAQs

1. Why use night-time light data for economic analysis?
It reflects real-time activity—urbanisation, industrial growth, and household well-being—without delays in official statistics.

2. Which districts in Bihar are showing the fastest growth?
Patna, Vaishali, Muzaffarpur, Gaya, and Begusarai.

3. Which districts are newly emerging as growth centers?
Arwal, Jehanabad, Jamui, Banka, and Madhubani.

4. Which sectors dominate Bihar’s growth in high-light areas?
Construction, retail trade, agriculture, animal husbandry, and small-scale enterprises.

5. How is night-time light data useful for governance?
It helps identify pockets of growth, plan infrastructure, and deliver services more effectively in rapidly expanding regions.