ELEANOR BROWN [*]
The idea of public life in America is premised on individual initiative. Democracy demands that citizens give public voice to their views; a market economy demands that people earn their keep. When they are not satisfied with the results of such large and largely impersonal institutions, Americans volunteer. In 1996, the most recent year in which a presidential election was held, 54.2 percent of the adult population voted; 63.2 percent worked; and 48.8 percent volunteered.  Although the proportion of the population volunteering in 1996 fell short of the proportion voting, the amount of time donated loomed large in contrast to the time it takes to vote: Volunteers gave an average of 4.2 hours of their time every week.  Delivering meals to shut-ins, raising money for the PTA, coaching Little League--in myriad ways, volunteers weave important pieces of the social fabric.
This article provides an overview of the scope of volunteering in the United States. It begins with the question "What is a volunteer?" and, with issues of definition and measurement in mind, surveys the available estimates of the size of the volunteer workforce. It then considers the purposes to which this labor is put. Turning from volunteer work to its workforce, it examines some determinants of volunteering, paying particular attention to factors shaping the volunteer activities of the young and the old.
A. What Is a Volunteer?
Scholars have striven to be precise in their usage of the word volunteer. One particularly thoughtful definition defines a volunteer as
an individual engaging in behavior that is not bio-socially determined (e.g., eating, sleeping), nor economically necessitated (e.g., paid work, housework, home repair), nor sociopolitically compelled (e.g., paying one's taxes, clothing oneself before appearing in public), but rather that is essentially (primarily) motivated by the expectation of psychic benefits of some kind as a result of activities that have a market value greater than any remuneration received for such activities. 
In short, volunteering is purposeful activity that is not compelled and the productive value of which is not captured by the volunteer.
One might quibble with the notion that volunteering needs to result in something that has market value, in contrast to activities that were intended to have market value but went awry, or ones that pursued goals not related to market value such as lobbying on behalf of unpopular causes. Generally, though, this definition is an apt one for the purposes at hand. It encompasses informal volunteering--good deeds done directly, such as shopping for a frail neighbor or babysitting for a harried one, unmediated by any formal organization, such as a church or a school, through which larger-scale volunteer efforts are coordinated. Such good deeds are not compelled, and they yield value that is not materially returned to the volunteer. The definition also extends to stipended volunteers. As the word "stipend" implies, programs such as AmeriCorps offer modest pay to doers of good works, on the theory that society needs full-time volunteers and that it is hard for very many people to give so much time freely and continu e to keep body and soul together. As long as stipended volunteers are employed in "activities that have a market value greater than any remuneration received," they are volunteers as defined above.
The boundaries to volunteering drawn by this definition are by no means universally employed, even among scholars. Ram Cnaan, Femida Handy, and Margaret Wadsworth survey this and other definitions of volunteering used in legal and academic sources, and identify four dimensions addressed by all of them: (1) the voluntary nature of the act; (2) the nature of the reward, whether entirely psychic or simply sufficiently unremunerative for the act to remain largely donative in nature; (3) the auspices under which the work is performed, either orchestrated by an organization or not necessarily so; and (4) the beneficiaries of the act and their relationship to the actor, be they strangers or simply removed from the family circle. …