Volunteers are more focused on what they want to do. Volunteers have to budget time commitment more. There are many more organizations in which to volunteer. More volunteers want one-time or short term volunteer opportunities. People are living longer.
Volunteers have an enhanced political awareness of volunteering.
More people use volunteering to support their careers. There are more legal liability concerns for volunteers. Volunteers often want to have more say in the organizations they support. New technology is broadening volunteer opportunities. More volunteer programs recruit their own clients as volunteers.