DO WE NEED MORE UNIVERSAL BASIC INCOME EXPERIMENTS?While the notion of universal basic income (UBI) has been around for many decades, the idea has recently gained more traction in the United States. A 2020 poll from the Pew Research Center found that almost half (45 percent) of survey respondents would support a guaranteed payment of $1,000 per month to all adults, regardless of their working status. Several politicians have campaigned in recent years on implementing a local or federal UBI, and stimulus payments during the COVID-19 pandemic have further heightened the debate.As more cities, states, and countries have experimented with implementing UBIs, there have been growing opportunities for researchers to understand the potential implications of this policy. For example, the Stockton Economic Empowerment Demonstration, which provides $500 monthly payments to a random selection of the city's residents, found that the payments increased financial stability, full-time employment, and health and wellness. These findings, along with those of other experiments, have drawn much attention as other cities consider implementing similar programs both in the U.S. and worldwide. However, researchers and policymakers are now facing a critical question: how much more evidence on the impacts of universal basic income is needed? That is, do we have enough evidence to support rolling out these programs more broadly, or are more experiments needed in order to further refine UBI policies and understand their potential effects?In this issue, Bru Laín, of the University of Barcelona, argues that while further experiments can be useful, the extensive evidence base that has already accumulated renders them unnecessary. Therefore, he feels that the establishment and implementation of UBI policies should not wait for further evidence. Amy Castro, of the University of Pennsylvania, and Stacia West, of the University of Tennessee -Knoxville, respond to Laín's argument by highlighting remaining gaps in the body of evidence on UBI. They assert that further experimentation is needed before widespread UBI adoption to ensure that well-intentioned programs do not result in far worse outcomes for the populations that they aim to support. In his response, Laín argues that the evidence is clear that UBI generates positive effects for the targeted population, hence justifying UBI policies, while he agrees with Castro and West about the need for additional research on effective UBI implementation.