An empirical Coasian study on the socio-economic profiles of two politically sensitive informal settlements: Kowloon Walled City and Rennie’s Mill

•Original landlord-tenancy analogy applied to informal settlements.•Coasian interpretation of resource implications of different institutional designs support by census data.•Case studies on self-help housing under uncertain jurisdiction and/or uncertain property rights. Informed by the “corollary of Coase Theorem” (Lai and Hung, 2008; Lai et al., 2007), for a better understanding of the self-help post-war development of two politically sensitive and vanished places in Hong Kong, the so-called “Kowloon Walled City” (Lai, 2016; Lai and Chua, 2017; Lau et al., 2018) and Rennie’s Mill (Lan, 2006), which have attracted academic interest but remained under-researched in terms of empirical scrutiny, this study: •Identify and compare their institutional arrangements by archival research;•identify and compare their development outcomes, as measured by census and other official data including mapping and photographic information, supplemented by published oral history of witnesses; and•establish and discuss the relationship between the differences in institutional arrangements and development outcomes in terms of a landlord-tenant analogy.