The number of volunteers increased last year despite the recession, the biggest one-year jump since 2003, according to a study released Tuesday.

The volunteer rate has been rising nationally for years, driven by factors including decades of presidential calls to action and greater emphasis on youth involvement through schools — but the increase in the midst of a punishing recession surprised some experts. Charitable donations fell last year, as some people seemed to choose to give time rather than money.

More than 63 million Americans volunteered last year, a bump of 1.6 million, according to the Corporation for National & Community Service (CNCS), an independent federal agency that runs AmeriCorps and other programs. That’s nearly 27 percent of all residents. Americans donated more than 8 billion hours of service in 2009, worth an estimated $169 billion to the economy.

“Folks throughout the country are looking around their communities, seeing people in pain and turning toward the problems, not away from them,” said Patrick Corvington, chief executive of CNCS. “It’s an important shift — folks want to get engaged, want to make a difference.”

At the same time, charitable giving dropped nearly 4 percent last year, to about $304 billion, according to a study by Giving USA Foundation and the Center on Philanthropy at Indiana University, which tracked donations by more than 75 million households and more than 1 million companies, as well as estates and foundations.