Before revision:  The probability of being invited increases with the size of the host department and if the scholar belongs to it. Having a coauthor in the host department increases the probability of being invited and accepting the invitation, whereas the distance between the host department and invited scholar reduces the probability of being invited and accepting the invitation.
After revision:  The probability of being invited increases with the size of the host department . Young and low-quality scholars have a higher probability of accepting an invitation. The distance between the host department and invited scholar reduces the probability of being invited and accepting the invitation.