Welfare states carry the promise of being both a safety net and a springboard for their citizens. Yet, under the weight of economic, demographic and technological transformations, their dual ambition is showing signs of strain. Against this backdrop of persistent poverty, labour market challenges and the limits of traditional welfare states, interest in a radical change in approach has intensified. Once dismissed as utopian, the idea of a universal basic income (UBI) has taken a spectacular flight in recent years. This dissertation engages directly with the structural challenges facing modern tax-benefit systems and critically examines the contested promise of universal basic income as a potential response. Throughout its five chapters, I seek to inform and advance ongoing policy debates by (i) mapping the current state of affairs regarding the inadequacy of safety nets and prevalence of dependency traps, (ii) stress-testing the impact of UBI, and (iii) exploring how its potential outcomes would shift public opinion on UBI. In order to do so, I employ microsimulation modelling in conjunction with representative household survey and administrative data, with a particular focus on Belgium and the Netherlands. My findings point towards hidden complexities and inevitable trade-offs beneath the surface. Important gaps indeed persist in income adequacy, particularly for jobless single parents, reflecting a stronger policy emphasis on in-work support than on unconditional protection. Yet, poverty and dependency traps are less widespread than assumed in the current policy discourse, though single parents remain a notable exception. Most importantly, UBI is not the silver bullet to these challenges it is often claimed to be. Its impact will depend critically on level, design and context. UBI also does not escape the very trade-offs that constrain traditional welfare state instruments. If anything, it renders them more visible. Public support for UBI will therefore be equally fair-weathered and contingent on its anticipated outcomes, as individuals care both about its impact on themselves personally and on society as a whole. As such, UBI should be treated as a configurable instrument rather than as a single fix, and as a complement rather than a substitute to existing tax-benefit systems. Overall, this dissertation argues that effective social protection needs carefully layered, complementary policy instruments that balance targeting with universality, poverty with work incentives and individualisation with household modulation.
