Kevin Lewis

February 09, 2019

The Welfare Effects of Social Media
Hunt Allcott et al.
NBER Working Paper, January 2019


The rise of social media has provoked both optimism about potential societal benefits and concern about harms such as addiction, depression, and political polarization. We present a randomized evaluation of the welfare effects of Facebook, focusing on US users in the runup to the 2018 midterm election. We measured the willingness-to-accept of 2,844 Facebook users to deactivate their Facebook accounts for four weeks, then randomly assigned a subset to actually do so in a way that we verified. Using a suite of outcomes from both surveys and direct measurement, we show that Facebook deactivation (i) reduced online activity, including other social media, while increasing offline activities such as watching TV alone and socializing with family and friends; (ii) reduced both factual news knowledge and political polarization; (iii) increased subjective well-being; and (iv) caused a large persistent reduction in Facebook use after the experiment. We use participants’ pre-experiment and post-experiment Facebook valuations to quantify the extent to which factors such as projection bias might cause people to overvalue Facebook, finding that the magnitude of any such biases is likely minor relative to the large consumer surplus that Facebook generates.

The Economic Effects of Facebook
Roberto Mosquera et al.
Texas A&M University Working Paper, December 2018


Social media permeates many aspects of our lives, including how we connect with others, where we get our news and how we spend our time. Yet, we know little about the economic effects for users. Using a large field experiment with over 1,765 individuals, we document the value of Facebook to users and its causal effect on news consumption and awareness, well-being and daily activities. Participants reveal how much they value one week of Facebook usage and are then randomly assigned to a validated Facebook restriction or normal use. Those who are off Facebook for a week reduce news consumption, are less likely to recognize politically-skewed news stories, report being less depressed and engage in healthier activities. One week of Facebook is worth $25, and this increases by 15% after experiencing a Facebook restriction (26% for women), reflecting information loss or that using Facebook may be addictive.

Information flow reveals prediction limits in online social activity
James Bagrow, Xipei Liu & Lewis Mitchell
Nature Human Behaviour, forthcoming


Modern society depends on the flow of information over online social networks, and users of popular platforms generate substantial behavioural data about themselves and their social ties. However, it remains unclear what fundamental limits exist when using these data to predict the activities and interests of individuals, and to what accuracy such predictions can be made using an individual’s social ties. Here, we show that 95% of the potential predictive accuracy for an individual is achievable using their social ties only, without requiring that individual’s data. We used information theoretic tools to estimate the predictive information in the writings of Twitter users, providing an upper bound on the available predictive information that holds for any predictive or machine learning methods. As few as 8-9 of an individual’s contacts are sufficient to obtain predictability compared with that of the individual alone. Distinct temporal and social effects are visible by measuring information flow along social ties, allowing us to better study the dynamics of online activity. Our results have distinct privacy implications: information is so strongly embedded in a social network that, in principle, one can profile an individual from their available social ties even when the individual forgoes the platform completely.

Communicating Resource Scarcity
Grant Donnelly et al.
Harvard Working Paper, January 2019


The development and maintenance of interpersonal relationships require investments of both money and time - resources that are often limited in supply, but in great demand. Indeed, consumers are regularly asked to dedicate their money and time to social engagements, and need to manage these resources efficiently. Therefore, consumers often choose to cite insufficient time or money as an excuse for rejecting social invitations. But how does using the excuse of financial versus time scarcity influence interpersonal relationships? Across eight experiments, we demonstrate that using financial scarcity as an excuse (e.g., “I don’t have money”) increases perceptions of interpersonal closeness and helping behavior compared to using time scarcity as an excuse (e.g., “I don’t have time”). This effect is explained by the fact that time is perceived as a more personally controllable resource than money, resulting in consumers who cite financial (vs. temporal) constraints as being perceived as more trustworthy. However, excuse-givers do not correctly predict this difference in interpersonal outcomes. These findings advance our theoretical understanding of how excuses revolving around resource constraints affect interpersonal perceptions and behaviors and provides practical insights for consumers desiring to minimize social repercussions when turning down social invitations.

Not all gifts are good: The potential practical costs of motivated gifts
Lara Aknin, Dylan Wiwad & Yuthika Girme
Journal of Applied Social Psychology, forthcoming


People rely on support from others to accomplish mundane and momentous tasks. When asking for assistance, is it beneficial to incentivize a helper by offering a motivated gift (i.e., a gift with the hope of getting support in return)? Six studies (N > 2,500) examine the frequency and potential costs of motivated gifts. In Study 1, a third of Americans indicated that they had given a motivated gift at least once, while nearly two‐thirds believed they had received one. In Studies 2a-d, most participants who imagined receiving a motivated gift before a favor request reported lower willingness to help and anticipated satisfaction from helping than participants who imagined simply being asked for a favor. Finally, Study 3 replicates these findings with actual help provided among friends in a laboratory setting. Findings suggest that motivated gifts are relatively common but may sometimes undermine the assistance that people hope to receive.

Collaboration, cognitive effort, and self-reference in United Kingdom top 5 pop music lyrics 1960-2015
Amanda Krause & Adrian North
Psychology of Aesthetics, Creativity, and the Arts, forthcoming


This research investigated associations between the lyrics of every song to have reached the weekly U.K. Top 5 singles chart from 1960 to 2015 and the number of people responsible for recording each song. Following computerized content analysis of the lyrics of the 4,534 unique songs, the results showed that the number of musicians involved was negatively related to use of cognitive terms, consistent with previous research on social loafing, and was also negatively related to instances of self-reference and use of language concerning social interaction, arguably in reflection of the inherent constraints on such that arise from collaborating with others.

Could peers influence intelligence during adolescence? An exploratory study
Ryan Charles Meldrum et al.
Intelligence, January-February 2019, Pages 28-34


For decades, scholars have examined various aspects concerning the development of intelligence. Little research, however, has considered the potential for peers to influence intellectual ability. To investigate this possibility, data collected on a sample of 892 adolescents and their best friends who participated in the Study of Early Child Care and Youth Development were analyzed. Results indicate that while a large bivariate association exists in a longitudinal model between peer and adolescent intelligence, it is reduced to non-significance after controlling for prior levels of adolescent intelligence and other background variables. As such, and contrary to a number of other literatures providing evidence of peer influences on developmental outcomes during adolescence, this study does not find evidence supporting a socialization effect of peers on intellectual ability. Limitations of the study and directions for future research are discussed.

Pettiness in social exchange
Tami Kim, Ting Zhang & Michael Norton
Journal of Experimental Psychology: General, February 2019, Pages 361-373


We identify and document a novel construct - pettiness, or intentional attentiveness to trivial details - and examine its (negative) implications in interpersonal relationships and social exchange. Seven studies show that pettiness manifests across different types of resources (both money and time), across cultures with differing tolerance for ambiguity in relationships (the United States, Switzerland, Germany, and Austria), and is distinct from related constructs such as generosity, conscientiousness, fastidious, and counternormativity. Indeed, people dislike petty exchanges even when the (petty) amount given is more generous (e.g., a gift card for $5.15 rather than $5), suggesting that pettiness may in some instances serve as a stronger relationship signal than are actual benefits exchanged. Attentiveness to trivial details of resource exchanges harms communal-sharing relationships by making (even objectively generous) exchanges feel transactional. When exchanging resources, people should be wary of both how much they exchange and the manner in which they exchange it.

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