This paper presents evidence from two randomized experiments testing the us
e of financial incentives to encourage labour market participation. The Sel
f-Sufficiency Project shows that supplementing earnings from low-paying, fu
ll-time jobs can increase employment among single parents who are long-term
welfare recipients, can raise their earnings and incomes, and may entail l
ittle net increase in government transfers net of taxes. In the Earnings Su
pplement Project, however, the offer to partially compensate unemployment i
nsurance recipients who returned to work quickly and experienced earnings l
osses had no impact on the labour force behaviour of repeat users of UI and
only a small and short-lived impact with displaced workers. The paper incl
udes a discussion of the issues that need to be addressed in trying to stim
ulate work effort using financial incentives and concludes with some lesson
s drawn from the research findings.