Based on detailed spatial population data from the Global Human Settlement Layer, the paper underlines that discouraging migration to cities is unlikely to significantly reduce city population growth.

The findings demonstrate that when incorporating the effects of reclassification, only 4 % of city population growth is due to migration and two-thirds of the growth is due to natural change, while reclassification accounts for 29 % of growth.

Ignoring reclassification would attribute city population growth entirely to migration and natural change due to more births than deaths.

The lack of generalised time series data on city boundaries has hindered the inclusion of reclassification effects in existing studies. The paper addresses this problem by measuring reclassification in a transparent manner. It applies a new harmonised definition of cities, towns, and rural areas to gridded population data between 1980 and 2020.

The paper is openly accessible via the following link: https://shorturl.at/rpRTE