Dhaka, Oct. 23 -- The perception of night has been fundamentally changed ever since the invention of artificial light. The nighttime is not just darkness; it has an economy of its own. It is known as the "nighttime economy" (NTE), a simple term for all the economic activity that happens between 6:00 P.M. and 6:00 A.M. However, the problem with the nighttime economy is that it is not separate from the urban economy. It is diverse in nature and spread throughout various components of the urban economic system.

Satellite imagery of nighttime lights (NTL) is used to assess the development of the urban economy (Ghost et al., 2013). In Bangladesh, where there is a scarcity of official data on the informal sector, NTL data serves as an alternat...