Table 2.

Scope of the analysis. Own categorization.

Scope	Description	Relevant articles
Local level	Studies covering one or several villages, local towns, city neighborhoods, or settlements	(36, 38, 40, 45, 52–58, 60, 61)
City level	Studies covering one or several cities	(31, 34, 35, 37, 39, 42, 43, 59) Nighttime light as proxy: (50)
Regional level	Studies covering one or several districts, provinces, or states	(32, 33, 41, 44); nighttime light as proxy: (66)
National level	Studies covering an entire country	Nighttime light as proxy: (48, 49, 51, 63)
International level	Studies covering at least two countries	Nighttime light as proxy: (46, 47, 64, 65)