The phrase “social capital” is used in (at least) two very different senses and discussions.

One is an Anglophone discussion among social scientists who seem generally comfortable with a liberal market order. Important participants include James Coleman, Robert Putnam, Elinor Ostrom and (using the related phrase “collective efficacy”) Robert Sampson and Felton Earls. These social scientists understand social capital as the value that derives from collaborating and solving collective-action problems together. It’s measured by rates of joining, socializing, participating in the institutions of civil society, and trusting one’s peers. It can exist in any group, regardless of wealth and prestige. For instance, Sampson, Earls and their colleagues found that levels of collective efficacy varied greatly among Chicago neighborhoods, independent of race and class.

The central hypothesis in this literature is that higher social capital predicts better outcomes (safety, education, health, employment). This hypothesis is often proven in empirical studies. The deepest explanation is that these desirable outcomes are public goods, subject to problems of collective action, and social capital is the capacity—inherent in a group—to address problems of collective action successfully. For instance, safe streets represent a public good, and when people voluntarily maintain order, the streets are safer.

The other discourse is loosely Marxian and of Continental European origin; the most influential theorist is Pierre Bourdieu. For Bourdieu, social capital can only be understood in relation to economic capital and cultural capital. All three forms are the result of past labor, which accumulates or materializes in forms that can then be owned and by–and used to the advantage of–specific individuals or closed groups, such as firms.

Economic capital means ownership, or the ability to own, the means of production (factories, offices, farms, mines). Cultural capital means personal characteristics that you can learn in order to set yourself apart as a member of an advantaged group. For example, if you know how to dress for and behave at a corporate job interview, you have acquired cultural capital. And social capital means membership in any group that has value for those who belong.

Thus a paradigm case of social capital for Bourdieu is being connected to specific aristocrats in a way that puts you within the group known as “the nobility.” You might be a poor and boorish noble: then you would have social capital without much economic or cultural capital. Still, each of the three pays off in ways that are fundamentally economic.

For Coleman et al., the effort required to build social capital is at least partly altruistic. When you try to help others around you, it turns out that you benefit as well from the public resource of social capital. Social capital is non-rivalrous or win/win. If poor people in Chicago build more social capital, that does no harm to Lake Shore millionaires. It might even reduce their tax burdens by boosting graduation rates and cutting crime in the city as a whole.

The Bourdieuian form of social capital is competitive and maybe even zero-sum. If you form a connection to an aristocrat that gives you a leg up in society, I am less advantaged. According to Bourdieu, people build social capital to advance their own interests, strategically targeting others who have various forms of capital to add to their networks:

The existence of a network of connections is not a natural given …  It is the product of an endless effort at institution. … In other words, the network of relationships is the product of investment strategies, individual or collective, consciously or unconsciously aimed at establishing or reproducing social relationships that are directly usable in the short or long term. …

The reproduction of social capital presupposes an unceasing effort of sociability, a continuous series of exchanges in which recognition is endlessly affirmed and reaffirmed. … This is one of the factors which explain why the profitability of this labor of accumulating and maintaining social capital rises in proportion to the size of the capital. Because the social capital accruing from a relationship is that much greater to the extent that the person who is the object of it is richly endowed with capital (mainly social, but also cultural and even economic capital), the possessors of an inherited social capital, symbolized by a great name, are able to transform all circumstantial relationships into lasting connections. They are sought after for their social capital and, because they are well known, are worthy of being known (‘I know him well’); they do not need to ‘make the acquaintance’ of all their ‘acquaintances’; they are known to more people than they know, and their work of sociability, when it is exerted, is highly productive.

Although these theories are different, they could both apply in a society as a whole. After a discussion with students last week, I am inclined to the following hypotheses:

1. Access to the highest rungs of socioeconomic advantage requires (or at least benefits from) Bourdieu-style social capital. If you want to get a seat on the Supreme Court, it seems almost necessary to attend Harvard’s or Yale’s law school, partly because of who you know as a result. Social capital may also get you into those law schools in the first place. For instance, I can think of someone who attended Law School on his way to federal judicial appointments; his mother had also been a judge, and his grandfather had attended Yale.
2. Well-being in the middle and lower rungs depends on social capital in the Coleman/Putnam sense. If you are trying to get through high school and obtain some post-secondary education, get a job, stay out of jail, and live to the median age, it’s very helpful to be embedded in networks of cooperation and mutual support. Those networks have value even if the other members are not rich and powerful.

See also: David Brooks/Pierre Bourdieu, Bourdieu in the college admissions office, Chua and Rubenfeld, The Triple Package, social capital and economic mobility, “social capital”: political and apolitical and when social advantage persists for millennia.