The role of social networks and social capital in creating economic resilience, exchange, and opportunity has been the focus of research across several fields, including sociology and economics. While it is impossible to do justice to this wide-ranging literature in the few short paragraphs available here, we next describe several research papers that have worked with particularly new and promising datasets. We encourage readers who are interested in obtaining more comprehensive overviews to start with recent review articles. Readers interested in more theoretical treatments could start with Jackson (
2011) and Jackson et al. (
2017), who discuss various economic applications of social networks, and Jackson (
2020), who provides a formal typology of measures of social capital and their interactions with network measures. Readers who are looking for an overview of empirical work on the economic effects of social networks might start with Kuchler and Stroebel (
2021), who review the role of social interactions in household financial decision-making, and Jackson (
2021), who summarizes the evidence on the interaction between social capital and economic inequality. In addition, several chapters of the
Handbook of Social Economics (edited by Benhabib,
2011) summarize the evidence on peer effects across a wide range of settings. Finally, for discussions of identification challenges in the peer effects literature, see Bramoullé et al. (
2020) and Kuchler and Stroebel (
2021).
21.2.1 Online Social Networking Services
The appeal of working with data from online social networking services is clear: these widely adopted services record social links between many individuals and even, in some cases, the strength of these ties. The scale of the most successful online social networks is astonishing. As of the second quarter of 2021, Facebook had 2.9 billion monthly active users—nearly 40 per cent of the world’s population—and as of their last reports, Twitter and LinkedIn each had over 300 million active users. WeChat, a China-based online platform that includes a substantial social networking element, had 1.25 billion users. The enormous user bases of these platforms dwarf the sample sizes traditionally studied by economists and social scientists and provide researchers not only with sufficient statistical power to detect granular patterns but also with data that is difficult or expensive to obtain directly via surveys.
Already, a number of researchers have worked with anonymized (individual-level) microdata from Facebook to study a broad range of economic and social outcomes. For example, Gee et al. (
2017) explore the extent to which weak and strong ties might help individuals find new jobs. Similarly, Bailey et al. (
2018a,
2019a,
b) study the role of social interactions in driving optimism in housing and mortgage markets. Bailey et al. (
2019a,
b) use data from Facebook to study the role of peer effects in product adoption, and Bailey et al. (
2020a) study the role of information obtained through friends on individuals’ social distancing behaviours during the COVID-19 pandemic. Bailey et al. (
2022) use data from Facebook to explore the determinants of the social integration of Syrian migrants in Germany.
Data from online social networking platforms can also be a rich record of cross-country and cross-regional connections. Using more aggregated data from Facebook—data we describe in more detail in Sect.
21.3.2—researchers have explored the historical and cultural drivers of social connectedness across European regions (Bailey et al.,
2020b), as well as the relationship between social connections and international trade flows (Bailey et al.,
2021), migration (Bailey et al.,
2018b), investment (Kuchler et al.,
2021), bank lending (Rehbein et al.,
2020), and the spread of COVID-19 (Kuchler et al.,
2020).
While Facebook is the largest online social networking platform in the world, other platforms—in particular those that offer different services and therefore measure different types of networks—are also valuable data sources for researchers. Jeffers (
2017) uses LinkedIn data on professional networks to study the role of labour mobility frictions in reducing entrepreneurship. Bakshy et al. (
2011) quantify the influence of Twitter users by studying the diffusion of information that they post, and Bollen et al. (
2011) measure the sentiment of Tweets to predict stock market movements. In a similar vein, Vosoughi et al. (
2018) examine the network structure of sharing behaviour on Twitter to document that false news often spreads faster and more widely than true news.
As illustrated by these studies, social networking platforms have information on a large set of variables. Besides the connections between pairs of individuals, these services collect data on the personal characteristics that users choose to share—for example, education, employment, and relationship status—as well as the content they produce or engage with (such as posts, messages, and “likes”). With advances in natural language processing (NLP) methods, which extract meaning from text, the latter type of data provides increasing opportunities for researchers to measure opinions and beliefs that are otherwise hard to capture at scale. A recent example is Bailey et al. (
2020a), who use Facebook posts to measure attitudes towards social distancing policies during the COVID-19 pandemic. (For a review of text mining and NLP research with Facebook and Twitter data, see Salloum et al. (
2017)). Moreover, many of these services record a rich set of metadata, including users’ log-in times and geographic locations. Several recent studies have exploited location data from Facebook to study social distancing behaviour during the COVID-19 pandemic (Ananyev et al.,
2021; Bailey et al.,
2020a; Tian et al.,
2022).
Similarly, most apps record information on the phone type used to log into the apps. Combined with other information, this can provide a proxy of a users’ income or socio-economic status (see Chetty et al.,
2022a,
b). Such data can be very helpful to researchers hoping to study the effects of social capital on outcomes such as social mobility. Indeed, many measures of social capital that the literature associates with beneficial outcomes relate to the extent to which relatively poor individuals are connected with relatively rich individuals—see, for example, the work of Loury (
1976), and Bourdieu (
1986), and the discussion in Chetty et al. (
2022a,
b). Measuring the variation of such “bridging capital” across regions or other groups requires information not only on networks but also on the income or socio-economic status of each individual node.
21.2.2 Other Communication Networks
The widespread adoption of smartphones has generated a trove of data capturing various aspects of economic and social behaviours. A large body of research has used smartphone location data—available from companies such as SafeGraph, Veraset, and Unacast—to study a range of topics, from the effect of partisanship on family ties (Chen & Rohla,
2018) to the role of staff networks in spreading COVID-19 in nursing homes (Chen et al.,
2021) to racial segregation and other racial disparities (Athey et al.,
2020; Chen et al.,
2020).
Another set of research has used call detail record (CDR) data to understand the economic effects of social networks. This literature includes Björkegren (
2019), who uses CDR data from Rwanda to study the spread of network goods (goods whose benefits to a user depend on the network of other users), as well as Büchel and Ehrlich (
2020) and Büchel et al. (
2020), who use CDR data to analyse how geographic distance impacts interpersonal exchange and how social networks affect residential mobility decisions, respectively.
Other sources of digital trace data suggest further avenues for advancing research on social networks and resilience. For example, researchers who wish to study the relationship between segregation and resilience might follow Davis et al. (
2019) in using data from services such as Yelp—a platform that allows users to review local businesses—to test whether people of different racial or socio-economic backgrounds visit the same parks, restaurants, hotels, stores, or other public places. Email and direct messaging networks can also offer insights into the structure of networks. For example, data on who communicates with whom within a corporation or community can allow researchers to establish how hierarchical organizations are, or how quickly information spreads within a community—both of which can be related to economic resilience and opportunity. For example, the analysis by Diesner et al. (
2005) of the Enron email corpus illustrates the patterns of communication within a collapsing organization. Data from other professional communication tools, such as Slack, Skype, or Bloomberg chat, might also offer insights into how the communications of traders and other finance professionals shape trading behaviour and asset prices.
21.2.3 Financial or Business Transaction Networks
One crucial way through which social networks bolster economic resilience is by providing a foundation for the flow of credit and insurance, and a long line of sociological research illustrates this phenomenon in myriad communities. An early example is Geertz’s (
1962) description of the rotating credit associations of small communities in Asia and Africa, where members periodically contribute money to a fund that can be claimed by each member on a schedule. More recently, Banerjee et al. (
2013) document how well-connected individuals in Indian villages—for instance, shopkeepers and teachers—play an essential role in spreading information about a microfinance programme.
But the importance of social networks in fostering access to financial resources is not limited to less-developed countries. In Europe, crowdfunding platforms such as GoFundMe and Kickstarter have hosted campaigns to help refugees, rescue small businesses during the COVID-19 recession, and finance individuals’ medical needs, educational expenses, or creative ventures. Data from such crowdfunding platforms is thus an interesting and valuable source of information for researchers hoping to measure the strength of social capital across communities. Social networks can also provide essential resources to small businesses. Two classic discussions in the literature are provided by Light (
1984), who attributes the entrepreneurial success of Korean immigrants in Los Angeles to social solidarity, nepotistic hiring, mutual support groups, and political connections, and by Coleman (
1988), who describes Jewish diamond merchants in New York City exchanging stones with each other for inspection, relying on close ethnic ties, rather than expensive formal contracts, as insurance against theft.
Furthermore, with the growth of online payment platforms (e.g. PayPal, Venmo, WeChat Pay, and Wise) and peer-to-peer lending websites (e.g. Zopa and LendingClub), it is increasingly possible to observe networks of financial transactions among friends and family as well as strangers. An example of work benefiting from such data is by Sheridan (
2020) who uses data from MobilePay, a Danish mobile payment platform, to measure social networks. Sheridan (
2020) shows that individuals’ spending responds to their friends’ unemployment shocks, thereby documenting that spending and consumption are linked across social networks. In an international context, remittances by immigrants to their home countries are an important economic force in many countries with substantial expat communities. Increasingly, such remittances are sent electronically, allowing for systematic measurement. We view the use of these types of data sources as highly promising directions for researchers interested in studying the contribution of various types of social capital to the resilience of communities.
21.2.4 Civic Networks
Although sociologists have characterized a central product of social networks—social capital—in various different ways (see the discussion in Chetty et al.,
2022a), one influential description by Putnam (
2000) emphasizes citizens’ participation in civic and community life, their respect for moral norms and obligations, and their trust in institutions and in one another. Digital trace data can be used to provide new ways of measuring these aspects of civic social capital.
A growing body of literature has used digital trace data to analyse the relationship between social networks and political trends, especially polarization. Employing innovative text, content, and sentiment analysis techniques, researchers have quantified patterns in political news and discourse on Facebook and Twitter (e.g. Alashri et al.,
2016; Engesser et al.,
2017; Moody-Ramirez & Church,
2019). Other work has found that individuals’ socio-economic backgrounds can predict their civic engagement on social media (e.g. Hopp and Vargo,
2017; Lane et al.,
2017) and that social media can drive their real-life political opinions and behaviours (e.g. Amador Diaz Lopez et al.,
2017; Bond et al.,
2017; Gil de Zúñiga et al.,
2012; Groshek and Koc-Michalska,
2017; Kosinski et al.,
2013). In particular, there has been enormous interest in researching the causes and consequences of “fake news” on social media (e.g. Allcott and Gentzkow,
2017; Guess et al.,
2019; Lazer et al.,
2018).
Besides Facebook and Twitter, other sources of digital trace data provide further opportunities to measure civic beliefs and behaviours and to construct measures of civic social capital. An emerging strand of research uses data from e-petition platforms—including governmental sites established by the White House (Dumas et al.,
2015) and the Bundestag (Puschmann et al.,
2017), as well as commercial sites such as
Change.org (Halpin et al.,
2018)—to study the forces that motivate citizens’ political engagement. Elnoshokaty et al. (
2016), for instance, have found that the success of petitions is more strongly driven by emotional elements than by moral or cognitive ones. Combined with records of online and offline social connections, this data offers the opportunity to study attitudes not only towards governmental policies and programmes but also towards those of communities such as universities and neighbourhood associations.