In an experiment in Illinois, members of a randomly selected group of unemployed individuals were offered a bonus of $500 if they found a job within 11 weeks and kept that job for four months. On average, people who were offered the bonus received UI for one week less than the control group, and the program saved more on UI benefits than it spent on bonuses.
Chapter 9, Social Insurance I: Social Security and Unemployment Insurance, p. 197 - Public Finance - International Edition - Sixth Edition