It is becoming more and more common to work freelance or take on short-term employment rather than permanent employment. The dream of freedom, being able to choose your work hours and to prioritise when and how you make a living could be part of the explanation why short-term employments and freelance assignments are becoming increasingly popular.
For you as a manager, short-term employments may make it easier to accommodate varying demand or a need to have a certain expertise available for a limited period of time.