Selected Articles

There is an emergent recognition among sociological theorists that luck may play a substantial role in life course achievement. There is also a nascent empirical literature that finds life outcomes to be unpredictable and unexpected life events to be a likely cause. A third literature of causal event studies provides thousands of point estimates of the life course consequences of random events. This review brings these literatures together under a unified framework.

Inequality in outcomes may emerge through a reinforcement process in which stochastic variation in values is determined by prior values but may also originate in preexisting differences in unobserved factors. A common approach toward differentiating between these origins in longitudinal data is to attribute systematic differences between units—differences in means or differences proportional to a time-varying group average—to unobserved heterogeneity. We show that any longitudinal data with systematic differences can also be produced by a reinforcement-driven data generating process. This result reconciles findings in three distinct research areas—science of science, personal culture, and sexual networks—where reinforcement is a strong theoretical prior, yet longitudinal data analyses advance an explanation of interpersonal differences based on heterogeneity. Future studies may bound the role of heterogeneity and reinforcement from below by measuring fixed traits that systematically vary with the outcome and isolating random events that trigger emergent differences.

Teams, juries, electorates, and committees must often select from various alternative courses of action what they judge to be the best option. The phenomenon that the central tendency of many independent estimates is often quite accurate—“the wisdom of the crowd”—suggests that group decisions based on plurality voting can be surprisingly wise. Recent experimental studies demonstrate that the wisdom of the crowd is further enhanced if individuals have the opportunity to revise their votes in response to the independent votes of others. We argue that this positive effect of social information turns negative if group members do not first contribute an independent vote but instead cast their votes sequentially such that early mistakes can cascade across strings of decision makers. Results from a laboratory experiment confirm that when subjects sequentially state which of two answers they deem correct, majorities are more often wrong when subjects can see how often the two answers have been chosen by previous subjects than when they cannot. As predicted by our theoretical model, this happens even though subjects’ use of social information improves the accuracy of their individual votes. A second experiment conducted over the internet involving larger groups indicates that although early mistakes on easy tasks are eventually corrected in long enough choice sequences, for difficult tasks wrong majorities perpetuate themselves, showing no tendency to self-correct.

Social influence may lead individuals to choose what is popular over what is best. Whenever this happens, it further increases the popularity advantage of the inferior choice, compelling subsequent decision makers to follow suit. The author argues that despite this positive feedback effect, discordances between popularity and quality will usually self-correct. Reanalyzing past experimental studies in which social information initially heavily favored inferior options, the author shows that in each experiment superior alternatives gained in popularity. This article also reports on a new experiment in which a larger number of subject choices allowed trials to be run to convergence and shows that in each trial the superior alternative eventually achieved popular dominance. To explain the persistent dominance of bestsellers, celebrities, and memes of seemingly questionable quality in everyday life in terms of social influence processes, one must identify conditions that render positive feedback so strong that self-correcting dynamics are prevented.

A classic thesis is that scientific achievement exhibits a “Matthew effect”: Scientists who have previously been successful are more likely to succeed again, producing increasing distinction. We investigate to what extent the Matthew effect drives the allocation of research funds. To this end, we assembled a dataset containing all review scores and funding decisions of grant proposals submitted by recent PhDs in a €2 billion granting program. Analyses of review scores reveal that early funding success introduces a growing rift, with winners just above the funding threshold accumulating more than twice as much research funding (€180,000) during the following eight years as nonwinners just below it. We find no evidence that winners’ improved funding chances in subsequent competitions are due to achievements enabled by the preceding grant, which suggests that early funding itself is an asset for acquiring later funding. Surprisingly, however, the emergent funding gap is partly created by applicants, who, after failing to win one grant, apply for another grant less often.

In the early twenty-first century, women continue to receive substantially less media coverage than men, despite women’s much increased participation in public life. Media scholars argue that actors in news organizations skew news coverage in favor of men and male-related topics. However, no previous study has systematically examined whether such media bias exists beyond gender ratio imbalances in coverage that merely mirror societal-level structural and occupational gender inequalities. Using novel longitudinal data, we empirically isolate medialevel factors and examine their effects on women’s coverage rates in hundreds of newspapers. We find that societal-level inequalities are the dominant determinants of continued gender differences in coverage. The media focuses nearly exclusively on the highest strata of occupational and social hierarchies, in which women’s representation has remained poor. We also find that women receive greater exposure in newspaper sections led by female editors, as well as in newspapers whose editorial boards have higher female representation. However, these differences appear to be mostly correlational, as women’s coverage rates do not noticeably improve when male editors are replaced by female editors in a given newspaper.

Seemingly similar individuals often experience drastically different success trajectories, with some repeatedly failing and others consistently succeeding. One explanation is preexisting variability along unobserved fitness dimensions that is revealed gradually through differential achievement. Alternatively, positive feedback operating on arbitrary initial advantages may increasingly set apart winners from losers, producing runaway inequality. To identify social feedback in human reward systems, we conducted randomized experiments by intervening in live social environments across the domains of funding, status, endorsement, and reputation. In each system we consistently found that early success bestowed upon arbitrarily selected recipients produced significant improvements in subsequent rates of success compared with the control group of nonrecipients. However, success exhibited decreasing marginal returns, with larger initial advantages failing to produce much further differentiation. These findings suggest a lesser degree of vulnerability of reward systems to incidental or fabricated advantages and a more modest role for cumulative advantage in the explanation of social inequality than previously thought.

Contemporary scholarship has conceptualized modern fame as an open system in which people continually move in and out of celebrity status. This model stands in stark contrast to the traditional notion in the sociology of stratification that depicts stable hierarchies sustained through classic forces such as social structure and cumulative advantage. We investigate the mobility of fame using a unique data source containing daily records of references to person names in a large corpus of English-language media sources. These data reveal that only at the bottom of the public attention hierarchy do names exhibit fast turnover; at upper tiers, stable coverage persists around a fixed level and rank for decades. Fame exhibits strong continuity even in entertainment, on television, and on blogs, where it has been thought to be most ephemeral. We conclude that once a person’s name is decoupled from the initial event that lent it momentary attention, self-reinforcing processes, career structures, and commemorative practices perpetuate fame.

Elizabeth Bruch and Rob Mare in “Neighborhood Choice and Neighborhood Change” (AJS 112 [2006]: 667–709) are to be commended for having extended Thomas Schelling’s highly stylized “thought experiment” on residential segregation to the empirical conditions observed in natural settings. Schelling demonstrated how segregation can occur even in populations that are tolerant of diversity so long as they are not outnumbered. Bruch and Mare challenge this conclusion, noting that “high levels of segregation occur only when individuals' preferences follow a threshold function” (p. 667), an assumption that they point out is not empirically plausible. On the basis of simulations with linear and empirical alternatives to Schelling's threshold function, they conclude that when “individuals are sensitive to even slight changes in neighborhood proportion own group” (p. 682) segregation largely disappears. However, we replicated their model and discovered their results were in error. Their empirical function leads to high segregation, not integration, and their linear function leads to integration only if neighborhood choice is sufficiently random that people readily move into neighborhoods where they do not want to live. Otherwise, linear preferences lead to more segregation than threshold preferences, the opposite of what they claim. We go further to show that sensitivity to slight changes in ethnic composition can even promote segregation in a population that not only tolerates diversity but actively seeks it.

When entrepreneurs enter structural holes in networks, they can exploit the related benefits. Evidence for these benefits has steadily accumulated. The authors ask whether those who strive for such structural advantages can maintain them if others follow their example. Burt speculates that they cannot, but a formal demonstration of this speculation is lacking. Using a game theoretic model of network formation, the authors characterize the networks that emerge when everyone strives for structural holes. They find that the predominant stable networks distribute benefits evenly, confirming that no one is able to maintain a structural advantage in the long run.