Last year was hard on megagift donors. Uneasiness about the country’s growing inequality revved up the criticism that often follows philanthropy by the wealthy: The gift does nothing for the common good; or it’s a pittance of the donor’s wealth.

In the Philanthropy 50, such critics will find ammunition. Ten of the billionaires on the list gave away less than 1 percent of their wealth. And more than $2 billion went to major American universities and colleges, many of which have enormous endowments.

Still, the Philanthropy 50 also offers a more appealing story. Many of 2015’s biggest gifts aim to drive social change, and several emerging philanthropists are making gifts to the needy.

Crossing the midpoint of the decade, big-gift philanthropy seems at a crossroads.