This study explores the use of nighttime luminosity data as a proxy for economic output, particularly in countries with poor statistical systems. The research compares luminosity data with standard economic data at the country and 1°×1° grid-cell levels from 1992 to 2008. The findings suggest that luminosity can provide valuable information for countries with low-quality data systems, especially those without recent population or economic censuses. Luminosity data are unique because they are objectively measured, highly correlated with economic output, and available globally since 1992. The study uses the G-Econ dataset, which provides output estimates at a high spatial resolution, to test the utility of luminosity data. The results show that luminosity can improve the accuracy of economic output estimates, particularly in regions with poor data systems. However, the reliability of luminosity data is limited in high-quality data systems due to high measurement errors. The study also finds that luminosity data are not reliable for low-output-density regions because the level of stable lights is too low to distinguish from background noise. The study concludes that luminosity data can be a useful supplement to current economic indicators in countries and regions with very poor quality or missing data. However, the results may overestimate the potential contribution of luminosity as a proxy for economic output in regions where stable lights are set at zero. The study also highlights the importance of using statistical approaches to proxy construction and the need for further research to improve the accuracy of luminosity-based economic estimates.This study explores the use of nighttime luminosity data as a proxy for economic output, particularly in countries with poor statistical systems. The research compares luminosity data with standard economic data at the country and 1°×1° grid-cell levels from 1992 to 2008. The findings suggest that luminosity can provide valuable information for countries with low-quality data systems, especially those without recent population or economic censuses. Luminosity data are unique because they are objectively measured, highly correlated with economic output, and available globally since 1992. The study uses the G-Econ dataset, which provides output estimates at a high spatial resolution, to test the utility of luminosity data. The results show that luminosity can improve the accuracy of economic output estimates, particularly in regions with poor data systems. However, the reliability of luminosity data is limited in high-quality data systems due to high measurement errors. The study also finds that luminosity data are not reliable for low-output-density regions because the level of stable lights is too low to distinguish from background noise. The study concludes that luminosity data can be a useful supplement to current economic indicators in countries and regions with very poor quality or missing data. However, the results may overestimate the potential contribution of luminosity as a proxy for economic output in regions where stable lights are set at zero. The study also highlights the importance of using statistical approaches to proxy construction and the need for further research to improve the accuracy of luminosity-based economic estimates.