Published Papers

We propose that stock-market participation is influenced by social interaction. In our model, any given "social" investor finds the market more attractive when more of his peers participate. We test this theory using data from the Health and Retirement Study, and find that social households-those who interact with their neighbors, or attend church-are substantially more likely to invest in the market than non-social households, controlling for wealth, race, education, and risk tolerance. Moreover, consistent with a peer-effects story, the impact of sociability is stronger in states where stock-market participation rates are higher.

A mutual fund manager is more likely to buy (or sell) a particular stock in any quarter if other managers in the same city are buying (or selling) that same stock. This pattern shows up even when the fund manager and the stock in question are located far apart, so it is distinct from anything having to do with local preference. The evidence can be interpreted in terms of an epidemic model in which investors spread information about stocks to one another by word of mouth.

Limited attention theory predicts that higher salience of earnings news implies a stronger immediate market reaction to earnings news and a weaker post-earnings announcement drift (PEAD) or reversal (PEAR). Using a new measure, SALIENCE, defined as the number of quantitative items in an earnings press release headline, we find strong evidence consistent with salience effects. Higher SALIENCE is associated with stronger announcement reaction and subsequent PEAR. Managers are more likely to choose higher SALIENCE before selling shares in the post-announcement period and when earnings are high, but less persistent, and to choose lower SALIENCE before stock option grants. The results are robust to using residual salience and an extended set of control variables. The findings are consistent with managers opportunistically headlining positive financial information in the earnings press release to incite over-optimism in investors with limited attention.

Conversation is a fundamental human experience that is necessary to pursue intrapersonal and interpersonal goals across myriad contexts, relationships, and modes of communication. In the current research, we isolate the role of an understudied conversational behavior: question-asking. Across 3 studies of live dyadic conversations, we identify a robust and consistent relationship between question-asking and liking: people who ask more questions, particularly follow-up questions, are better liked by their conversation partners. When people are instructed to ask more questions, they are perceived as higher in responsiveness, an interpersonal construct that captures listening, understanding, validation, and care. We measure responsiveness with an attitudinal measure from previous research as well as a novel behavioral measure: the number of follow-up questions one asks. In both cases, responsiveness explains the effect of question-asking on liking. In addition to analyzing live get-to-know-you conversations online, we also studied face-to-face speed-dating conversations. We trained a natural language processing algorithm as a "follow-up question detector" that we applied to our speed-dating data (and can be applied to any text data to more deeply understand question-asking dynamics). The follow-up question rate established by the algorithm showed that speed daters who ask more follow-up questions during their dates are more likely to elicit agreement for second dates from their partners, a behavioral indicator of liking. We also find that, despite the persistent and beneficial effects of asking questions, people do not anticipate that question-asking increases interpersonal liking.

Stock market investment decisions of individuals are positively correlated with those of coworkers. Sorting of unobservably similar individuals to the same workplaces is unlikely to explain this pattern, as evidenced by the investment behavior of individuals who move between plants. Purchases made under stronger coworker purchase activity are not associated with higher returns. Moreover, social interaction appears to drive the purchase of within-industry stocks. Overall, we find a strong influence of coworkers on investment choices, but not an influence that improves the quality of investment decisions.

We study the relation between households' stock purchases and stock purchases made by their neighbors. A ten percentage point increase in neighbors' purchases of stocks from an industry is associated with a two percentage point increase in households' own purchases of stocks from that industry. The effect is considerably larger for local stocks and among households in more social states. Controlling for area sociability, households' and neighbors' investment style preferences, and the industry composition of local firms, we attribute approximately one-quarter to one-half of the correlation between households' stock purchases and stock purchases made by their neighbors to word-of-mouth communication.

Five studies explore the self-presentational consequences of refusing to "back down" -- that is, upholding a stance despite evidence of its inaccuracy. Using data from an entrepreneurial pitch competition, Study 1 shows that entrepreneurs tend not to back down even though investors are more impressed by entrepreneurs who do. Next, in two sets of experiments, we unpack the psychology underlying why actors refuse to publicly back down and investigate observers' impressions of those actors. Specifically, we show that observers view people who refuse to back down as confident but unintelligent, and these perceptions drive consequential decisions about such refusers, such as whether to invest in their ideas (Studies 1 & 2) or whether to hire them (Study 3). Although actors can intuit these effects (Study 4), this understanding is not reflected in their behavior because they are concerned with saving face (Study 5).

This study examines culture and personality differences in student reports of the likelihood that they would post various types of information on their Facebook profiles. As predicted those high on conscientiousness, agreeableness, and emotional stability proved significantly less likely to report posting problematic content (e.g., substance abuse, sexual content) on their profile. Those who scored high on Compulsive Internet Use indicated a greater likelihood to post such profile information. Consistent with our expectations, our cross-cultural analysis revealed that US students were more inclined than German students to post problematic information to their Facebook site. Implications of these results and recommendations for future research are discussed.

Peer performance can influence the adoption of financial innovations and investment styles. We present evidence of this type of social influence: recent stock returns that local peers experience affect an individual's stock market entry decision, particularly in areas with better opportunities for social learning. The likelihood of entry does not decrease as returns fall below zero, consistent with people not talking about decisions that have produced inferior outcomes. Market returns, media coverage, local stocks, omitted local variables, short sales constraints, and stock purchases within households do not seem to explain these results.

We review an empirical literature that studies the role of social interactions in driving economic and financial decision-making. We first summarize recent work that documents an important role of social interactions in explaining household decisions in housing and mortgage markets. This evidence shows, for example, that there are large peer effects in mortgage refinancing decisions and that individuals's beliefs about the attractiveness of housing market investments are affected by the recent house price experiences of their friends. We also summarize recent work showing that social interactions affect the stock market investments of both retail and professional investors as well as household financial decisions such as retirement savings, borrowing, and default. Along the way, we describe a number of easily accessible recent data sets for the study of social interactions in finance, including the Social Connectedness Index, which measures the frequency of Facebook friendship links across geographies. We conclude by outlining several promising directions for further research in the field of social finance.

How do individuals decide to become entrepreneurs and learn to make optimal entrepreneurial decisions? The concentration of entrepreneurs in regions such as Silicon Valley has stimulated research and policy interest into the influence of peers, but the causal effect is hard to identify empirically. We exploit the exogenous assignment of students into business-school sections to identify the causal effect of entrepreneurial peers. We show that, in contrast to prior findings, a higher share of entrepreneurial peers decreases, rather than increases, entrepreneurship. The decrease is driven by a reduction in unsuccessful entrepreneurial ventures; the effect on successful ventures is significantly more positive.

Using the Panel Study of Income Dynamics, we document that controlling for observable characteristics, household investors' likelihood of entering the stock market within the ensuing five years is about 20% to 30% higher if their parents or children had entered the stock market during the previous five years. By eliminating competing hypotheses such as preference similarity and herding, we argue that these findings highlight the significance of information sharing regarding household financial decisions.