Using night light reflectance to measure economic output in syria

Introduction 

Regional estimates of gross domestic product (GDP) do not exist for Syria, but night light reflectance data (NLRD) collected in sets of satellite imagery is useful for disaggregating estimates of national economic output. Using two common satellites that capture night light reflectance, we calculate inflation-adjusted (real) GDP for all Syrian subdistricts from 2000 to 2020, which covers the pre-war and conflict economy. Our methodology was adopted from similar past research and uses NLRD to disaggregate and improve national GDP estimates.

The results highlight the urbanization of the Syrian economy before the war, and the economic devastation inflicted by the ongoing conflict, particularly in the northwest and areas formerly occupied by ISIS. NLRD is also useful for assessing urban development and electricity provision, and is a modest indicator of the spatial concentration of building damage. HAT will share the subdistrict-level real GDP estimates produced in this report upon request, which can be easily aggregated into higher geographies (for example at governorate level), to assist humanitarian and development actors plan livelihood, resilience, and redevelopment programming.

This paper presents the second quantitative measurement developed by the Syria HAT team in 2021, as HAT continues to grow and develop the humanitarian data landscape. These quantitative measurements aim to fill existing data gaps and to develop unified methodologies that can be applied across all areas of control.

The financial losses caused by the Syrian conflict are currently estimated at (US) $324.5 billion.1 However, while there are country level estimates of the economic costs of conflict, subnational economic estimates are almost non-existent, while those that do exist have questions over their accuracy. In order to fill this gap, and to build on the data landscape for Syria, Syria HAT has developed a proxy indicator for economic activity using night lights reflectance data (NLRD) collected by satellites which provide a consistent measurement of economic activity that can be applied across all zones of control and over time. This paper uses night light reflectance data to disaggregate and correct GDP estimates for Syria and analyze levels of subnational economic activity. Reliable subnational GDP estimates allows for further economic analysis measuring the drivers of growth, which will become more essential as more effort and resources are dedicated to rebuilding Syria.

The disaggregated regional GDP estimates calculated in this report are used to identify economic patterns within zones of control, governorates, and at the subdistrict level. Given their strong positive relationship to economic output, night light reflectance values are also useful for detailed spatial analysis at the city level, where changes in urban development can be monitored. Further, the data is also useful for rapid damage assessments or electricity availability assessments because contemporary nightlights data is released daily and monthly with only a short delay.

The analytical results highlight and confirm regional economic trends that emerged in the 2000s, as well as those since the onset of conflict in 2011. Specifically, the results show that economic growth in Syria was centered on urbanization in the 2000s and shifted to areas that produce energy and remained relatively free of conflict, particularly Al-Hasakeh. The results also show what areas have been the slowest to recover, specifically, northwest Syria and the eastern desert, due to ongoing political violence and occupation by ISIS.

These estimates of regional real GDP provide otherwise unavailable information on where and to what extent economic damage and recovery have occurred, which we intend to share publicly to assist humanitarian and development efforts in efficiently and equitably rebuilding the Syrian economy.