Charitable giving in America has never been just for rich people. Throughout our history, Americans of all walks of life have voluntarily given their time and money to help others, support cherished private institutions, and solve problems in their community. Some of the most generous people, proportionate to their income, have been the working poor.

But the broad-based character of American charity is now in jeopardy. Three recent studies show an alarming decline in the number of givers over the past decade.