The objective of this article is to determine, as conclusively as possible, if the implementation
of a Universal Basic Income (UBI) would lead to a significant reduction in the working age population
labour supply. If this were true, implementation of a UBI may not be sustainable. To do this, we will
compile empirical evidence from studies over the last few decades on the effects of implementation of a
UBI on employment. We apply the PRISMA methodology to better judge their validity, which ensures
maximum reliability of the results by avoiding biases and making the work reproducible. Given that
the methodologies used in these studies are diverse, they are reviewed to contextualize the results
taking into account the possible limitations detected in these methodologies. While many authors have
been writing about this issue citing experiences or experiments, the added value of this article is that it
performs a systematic review following a widely tested scientific methodology. Over 1200 documents
that discuss the UBI/employment relationship have been reviewed. We found a total of 50 empirical
cases, of which 18 were selected, and 38 studies with contrasted empirical evidence on this relationship.
The results speak for themselves: Despite a detailed search, we have not found any evidence of a
significant reduction in labour supply. Instead, we found evidence that labour supply increases
globally among adults, men and women, young and old, and the existence of some insignificant
and functional reductions to the system such as a decrease in workers from the following categories:
Children, the elderly, the sick, those with disabilities, women with young children to look after,
or young people who continued studying. These reductions do not reduce the overall supply since it
is largely offset by increased supply from other members of the community.