Background
A large body of evidence indicates the importance of upstream determinants to health. Universal Basic Income (UBI) has been suggested as an upstream intervention capable of promoting health by affecting material, biopsychosocial and behavioural determinants. Calls are emerging across the political spectrum to introduce an emergency UBI to address socio-economic insecurity. However, although existing studies indicate effects on health through cash transfers, UBI schemes have not previously been designed specifically to promote health.

Methods
In this article, we scope the existing literature to set out a set of interdisciplinary research challenges to address in designing a trial of the effectiveness of UBI as a population health measure.

Results
We present a theoretical model of impact that identifies three pathways to health impact, before identifying open questions related to regularity, size of payment, needs-based supplements, personality and behaviour, conditionality, and duration.

Conclusions
These results set, for the first time, a set of research activities required in order to maximise health impact in UBI programmes.

Keywords: Public health; Universal Basic Income; public policy; socio-economic status