This is a guest post from Marjorie Ringrose, Director of Social Impact at Social Venture Partners Boston. While it uncomfortably discounts the tremendous joy and value that comes with volunteering, there’s a volunteer-to-fundraising calculus that nonprofit and philanthropic leaders intuitively understand. People who volunteer for an organization are more likely to donate to it. They give larger contributions and donate more often and for longer periods of time than those who don’t volunteer.