EXECUTIVE SUMMARY: The United States has experienced declines in adults’ rates of volunteering with organizations and charitable giving over the last two decades. Because these behaviors generate wide-ranging benefits for communities as well as the volunteers themselves, it is essential to figure out how to turn around these downward trends. First we need to better understand the societal factors driving these declines. Research on volunteering with organizations has frequently focused on the health benefits that older volunteers enjoy, and the positive effects of volunteering for children and adolescents. These studies fit into a larger literature on the benefits of prosocial behavior, which can include giving to charity and in...