There are many situations which necessitate a change in permissions and even ownership of a folder.
If for some reason you no longer need to be an owner or collaborator on a folder, you can use the drop-down menu by your name to change your status.
If for example, you are no longer involved in a project, you may need to give ownership of the project-related folder to another person. This can only be done by the folder owner and once that person has already been invited as a collaborator(co-owner/editor/etc.). Changing a collaborator's role to 'owner' will grant them full ownership of a folder.
Another possibility is that you have files in your personal, non-UCSB Box account which you would like to move to your UCSB Box account:
1. Invite your UCSB account to be a collaborator (use your UCSBNetID@ucsb.edu as the invite email).
2. Set your UCSB account's permission to 'co-owner.'
3. After your UCSB account has 'accepted' that invitation (it is set to auto-accept by default), you can change your UCSB account to the full 'owner.'