Social capital refers to "the connections among individuals' social networks and the norms of reciprocity and trustworthiness that arise from them." (p 19) Much like the economic concepts of physical and human capital, the social networks of social capital are thought to have value. Bowling Alone empirically demonstrates a drop in social capital in contemporary America, identifies the cause and consequences of this drop, and suggests ways to improve social capital in the future. Though social capital varies across many dimensions, according to Putnam. the most important distinction is between bridging (inclusive) and bonding (exclusive) social capital. Bonding social capital networks are inward-looking and tend to reinforce exclusive identities and homogenous groups. Examples of such networks include ethnic fraternal organizations and country clubs. On the other hand, bridging social capital networks are outward looking and include people across "diverse social cleavages." Examples of bridging social capital include the civil rights movement and youth service groups. In general, bonding networks are most useful when specific reciprocity and mobilizing solidarity is necessary for "getting by" in oppressive situations. Bridging networks are good for linking to external assets and for information diffusion for the purpose of "getting ahead" of the status quo. As Putnam put it, "bonding social capital constitutes a kind of sociological superglue, whereas bridging social capital provides a sociological WD-40" (p 23). While useful for analytical purposes, this bonding/bridging distinction is not an "either or" category, but is rather a "more or less" dimension. That is, social capital can (and usually does) exist in both a bonding and a bridging forms simultaneously. For example: a black church may bond individuals based on race and religious belief, but bridge individuals across class lines. Having described what social capital is, Putnam turns his attention to how it has changed over time by conducting a meta-analysis of a large body of data from various sources. In doing so, he identifies a dominant theme: "For the first two-thirds of the twentieth century a powerful tide bore Americans into ever deeper engagement in the life of their communities, but a few decades ago--silently, without warning--that tide reversed and we were overtaken by a treacherous rip current" (p 27). Thus, social capital increased in the US until the 1970s and then suddenly decreased right up to the present. This theme is consistent across seven separate measures of social capital, including: political participation, civic participation, religious participation, workplace networks, informal networks, mutual trust, and altruism. Though most measures indicate a significant drop in social capital over the last three decades, Putman identifies four exceptions: an increase in volunteerism among youth, the growth in telecommunications, grassroots activity among evangelical conservatives, and an increase in self-help support. However, these exceptions do not offset the overall trend, indeed, by virtually every conceivable measure, social capital has eroded steadily and sometimes dramatically over the past two generations." (p 287) To identify why this might be, Putnam looked to see "whether the declines in civic engagement (social capital) are correlated across time and space with certain social characteristics" (p 185). Once he identified a correlation, he applied three additional tests to ensure the validity of potential causal factors. First, all correlations he identified had to lack spuriousness. Second, the proposed explanatory factor had to change in the relevant way. Finally, the direction of causation (result vs. cause) was questioned. Using these standards, Putnam rejected several common explanations for the contemporary drop in social capital, none of which were found to have had a statistically significant effect. These included educational deficiency, destruction of the nuclear family, race and racism, big government and the welfare state, and market economics. Additionally he identified four social characteristics that passed his tests of validity: pressures of time and money, mobility and sprawl, television, and generational differences. The lion's share (up to 50%) of the change in social capital over the last three decades is thought to be attributable to generational differences. People born in the 20s and 30s are significantly more socially connected than later generations, largely as a result of social habits and values developed during the "great mid-century cataclysm" or World War II. Generational differences are also synergistic with TV, as different generations have different habits regarding TV. As a whole, TV is thought to contribute up to 25%, the pressures of time and money, about 10%, and sprawl another 10% because it takes more time to get places. Sprawl is hence associated with increasing social segregation, and it disrupts community "boundedness". This leaves at least 15% unexplained. But does it really matter that social capital is declining? Putnam argues that, indeed, it does, as social capital "has many features that help people translate aspirations into realities." (p 288) Putnam identifies five such features. First, social capital makes collective problems easier to resolve, as there is less opposition between parties. This results in improved social environments, such as safer and more productive neighborhoods. Second, it makes business transactions easier, since when people trust each other, there is less of a need to spend time and money enforcing contracts. As a result, economic prosperity increases generally. Third, social capital widens our awareness of our mutual connectivity. This can improve the quality of our civic and democratic institutions. Fourth, it helps to increase and speed up the flow of information, which, in turn, improves education and economic production. Finally, social capital improves our health and happiness through both psychological and biological processes which require human contact. Unfortunately the effects of social capital are not always positive. Indeed, bonding social capital, in particular, can lead to destructive divisions within and between societies as groups develop a collective identity based largely on exclusion. But the "classical liberal argument" against community (or social capital networks) is its potential to restrict freedom and tolerance. Closely-linked communities (those with high social capital) can restrict individual freedoms through social pressure, especially if tolerance and freedom are not values of the community. Putnam acknowledges that this can happen, but it is not an inherent effect of social capital. In fact, he provides evidence to the contrary which suggests that, "Far from being incompatible, liberty and fraternity (or bonding social capital) are mutually supportive, and this remains true when we control for other factors" (p 356). Another argument against community holds that social capital can encourage inequality by concentrating wealth in closed communities. Again, Putnam acknowledges that this can happen, but is not a necessary consequence of community or social capital. Instead he argues that while "[s]ocial inequalities may sometimes be embedded in social capital ...both across space and across time, equality and fraternity (bonding social capital) are strongly positively correlated." (p 358-359). Thus, while social capital can, at times, restrict freedom, and enhance inequality, it does not inherently do so. On the contrary, empirical evidence suggests that social capital, freedom, and equality are in general, mutually reinforcing. But what can we do to improve our social capital? According to Putnam, we should first learn from the past where "lessons can be found in a period uncannily like our own" (p 367). The period he is referring to consists of roughly 1870-1915. During this time "dramatic technological, economic, and social change rendered obsolete a significant stock of social capital" (p 368) due to industrial revolution, urbanization, and waves of new immigration. In response, the leaders of the day re-developed social capital with an "extraordinary burst of social inventiveness and political reform" (p 368), which included the founding or refurbishing of most of our contemporary civic institutions such as the Boy Scouts, the NRA and the NAACP. While the specific reforms of this time period "are no longer appropriate for our time...the practical, enthusiastic idealism of that era--and its achievements-- should inspire us" (p 401). In this vein, Putnam makes general suggestions in seven "spheres deserving special attention" with the intention of encouraging readers to develop contemporary innovative solutions. 1. First, he suggests educational reforms be undertaken, including improved civics education, well designed service learning programs, extra curricular activities and smaller schools. 2. He argues for a more family-oriented workplace which allows for the formation of social capital on the job. 3. He encourages further efforts at new urbanism. 4. He would like to see religion become both more influential and at the same time more tolerant. 5. The technologies that reinforce, rather than replace, face-to-face interaction should be encouraged. 6. Art and culture should become more interactive. 7. Finally, politics requires campaign reforms and a decentralization of power. Conclusion In this important book, Putnam demonstrates that social capital increased between 1900 and the late 1960s and then dramatically decreased, largely as a result of generational succession, television, urban sprawl and the increasing pressures of time and money. This has resulted in an increase in a variety of social problems ranging from ineffective education to economic strain, to social conflict between individuals as well as groups. The solution to these problems likely rests with re-developing social capital, much like was done in the Progressive Era (but with solutions designed for contemporary America). Though not inherent to community development, such a project must take into account the potential of social capital to limit liberty and equality. This is particularly true when developing bonding social capital which is unfortunately much easier to develop than bridging social capital as, "Social capital is often most easily created in opposition to something or someone else." (p 361) While bonding social capital can help oppressed people to "get by" through solidarity, bridging social capital is required to "get ahead" through increased generalized norms of reciprocity. The development of innovative forms of such social capital is Putnam's ultimate challenge to the reader.