Atlas of Giving: U.S. Charitable Giving Tops $450 Billion in 2014

Mitchell says the impact of donor-advised funds on giving is enormous and growing. "In 2014, donor-advised funds accounted for $29.4 billion in giving. That's 6.4 percent of all giving in the U.S." Mitchell noted.

While donations to churches and religious causes remains the largest giving category, representing one third of all gifts, giving to religious organizations grew at a rate of only 6.4 percent in 2014. Comparatively, gifts to human services/disaster relief organizations increased 12.7 percent, while gifts to environmental causes and educational institutions rose 11.8 percent and 11.5 percent, respectively.