I appreciate the thoroughness and acknowledgement about limitations:
There is an obvious research evidence gap in the evaluation of an experimental, sustained UBI, which is considered the ‘gold standard’ for evidence. There is a shortage of evidence that meets most or all of the definitional features of a UBI, and the interventions covered by this report vary significantly. To arrive at conclusions at what may occur if all core features were unified into UBI policy, reviews have synthesized evidence from interventions that may not meet the most stringent definitions of universality or unconditionality.