Bretscher’s letter in PNAS (1) argues that structures for diversifying the types of research that are feasible could be sufficient to jolt fields free of ossified canon. In particular, he proposes creating a grant track with panels composed of experts in neighboring fields alongside the existing funding process with in-field panel members. Initiatives such as these foster the development of more novel, less-canonical ideas by adding to the opportunity structure (what research is feasible or convenient) within a field. Providing researchers funding and time to engage in extracanonical investigations may ameliorate one of the problems we listed … [↵][1]1Email: johan.chu{at}kellogg.northwestern.edu. [1]: #xref-corresp-1-1

Microbial communities are found throughout the biosphere, from human guts to glaciers, from soil to activated sludge. Understanding the statistical properties of such diverse communities can pave the way to elucidate the common mechanisms ...Multiple ecological forces act together to shape the composition of microbial communities. Phyloecology approaches—which combine phylogenetic relationships between species with community ecology—have the potential to disentangle such forces but are often ...

In many academic fields, the number of papers published each year has increased significantly over time. Policy measures aim to increase the quantity of scientists, research funding, and scientific output, which is measured by the number of papers produced. These quantitative metrics determine the career trajectories of scholars and evaluations of academic departments, institutions, and nations. Whether and how these increases in the numbers of scientists and papers translate into advances in knowledge is unclear, however. Here, we first lay out a theoretical argument for why too many papers published each year in a field can lead to stagnation rather than advance. The deluge of new papers may deprive reviewers and readers the cognitive slack required to fully recognize and understand novel ideas. Competition among many new ideas may prevent the gradual accumulation of focused attention on a promising new idea. Then, we show data supporting the predictions of this theory. When the number of papers published per year in a scientific field grows large, citations flow disproportionately to already well-cited papers; the list of most-cited papers ossifies; new papers are unlikely to ever become highly cited, and when they do, it is not through a gradual, cumulative process of attention gathering; and newly published papers become unlikely to disrupt existing work. These findings suggest that the progress of large scientific fields may be slowed, trapped in existing canon. Policy measures shifting how scientific work is produced, disseminated, consumed, and rewarded may be called for to push fields into new, more fertile areas of study.

MARIA ABASCAL MABEL ABRAHAM SETH ABRUTYN GABRIEL ACEVEDO PETER ACHTERBERG RADHA ADHIKARI JAE WAN AHN MARIA AKCHURIN RICHARD D. ALBA ARTHUR S. ALDERSON MARYAM ALEMZADEH SCOTT W. ALLARD KEERA ALLENDORF RACHEL ALLISON JUTTA ALLMENDINGER ZACK ALMQUIST DAVID L. ALTHEIDE CLAIRE ALTMAN ANTHONY ALVAREZ EDWIN AMENTA WEIHUA AN JOEL ANDREAS MEGAN ANDREW KENNETH T. ANDREWS RONALD ANGEL HILLARY ANGELO SNEHA ANNAVARAPU AMY ANSELL ROBERT J. ANTONIO RAWAN MAZEN ARAR MARIANA C. ARCAYA NOAH ARJOMAND ELIZABETH A. ARMSTRONG BRIAN ARONSON ASAD L. ASAD NOAH ASKIN PATRIK ASPERS ANSON AU

This paper demonstrates how increased competition entrenches dominants-a causal relationship I term durable dominance. Established theories of sustained dominance predict that a dominant's grasp on its position weakens when resources become widely available and the number of competitors increases. This prediction stems from the assumption, from economics, that sustained dominance is only possible when competition is limited; perfectly competitive markets with large numbers of competitors, widely accessible resources, and no barriers to entry provide no basis for dominants to maintain their size. I challenge this assumption, first arguing that a dominant can benefit when the number of its competitors increases, garnering more consumer recognition and facing fewer challenges from its nearest competitors, then asserting that even when a dominant does not directly benefit, increased competition can decrease nondominants' motility-magnitude of size changes-trammeling their growth to dominant size. Numerical simulations show reduced motility significantly lengthens the expected duration of a dominant's reign when many new competitors enter the market. Durable dominance reverses established understandings of competitive dynamics and holds implications for an increasing number of settings as markets become global and financialized, and scalable resources for production and distribution become widely available.

We argue that paradigmatic progress may be slowed as scientific fields grow large. This assertion is supported by evidence from citation patterns across 251 fields—over 1 billion citations among 57 million papers over 54 years—covered by the Web of Science dataset. A deluge of papers in a scientific field does not lead to quick turnover of central ideas, but rather to the ossification of canon.

U.S. corporations have shared members of their boards of directors since the early 1900s, creating a dense interlock network in which nearly every major corporation was connected through short paths and elevating a handful of well-connected directors to an influential inner circle. This network remained highly connected throughout the 20th century, serving as a mechanism for the rapid diffusion of information and practices and promoting elite cohesion. Some of the most well-established findings in the sociology of networks sprang from this milieu. In the 2000s, however, board recruiting practices changed: the authors find that well-connected directors became less preferred. As a result, the inner circle disappeared and companies became less connected to each other. Revisiting three classic studies, on the diffusion of corporate policies, on corporate executives' political unity, and on elite socialization, shows that established understandings of the effects of board interlocks on U.S. corporations, directors, and social elites no longer hold.

AbstractCorporate governance describes the process that allocates power and resources within organizations and the societal institutions that shape how they look, how they make decisions, and how the proceeds from their activities are divided. Research and theory traditionally focused on the institutions that overcome the separation of ownership and control created by dispersed shareholdings. Critics noted that this problem was distinctively American, and that corporate governance is shaped by history, culture, and power. We describe several domains for productive future research that is comparative, historical, and attentive to power dynamics.

This study presents theory that shows how increased competitive entry and decreased advantages of scale in an industry can benefit and entrench incumbent dominants, when important resources are scalable and widely-available. An initial test of the proposed theory using thirty years of data on competition among mutual funds supports the theory’s predictions: While increased entrepreneurial entry reduced investment flows into incumbent funds on average, dominant mutual funds—those with orders of magnitude higher assets under management compared to competitors with similar portfolio holdings—benefited from increased competition. Heightened entrepreneurial entry increased flows into dominant funds and entrenched them in their dominant positions. The theory holds potential implications across a variety of industry and non-industry settings.

This paper analyzes the properties of the board interlock network connecting large American corporations between 1997 and 2010. We find that the former stability of the network—in which a handful of banks and multinationals held positions at the center, a few dozen directors served on a large number of boards, and thus the distance between any two companies or directors was short—has largely collapsed during the past decade. There is no longer a stable core of companies that reliably occupies a center, and the mean geodesic has gone up continuously since 2002. The proximal cause is that no cohort of super-connector directors has arisen to take the place of those who have retired. This contrasts with prior generations, in which ambitious individuals sought out multiple board seats for the benefits they provided in status, business connections, and monetary compensation. We close by speculating on the implications of our findings for studies of the American elite.

This paper analyzes the properties of the board interlock network connecting the largest American corporations between 1999 and 2009. We find that the former stability of the network—in which a handful of banks and multinationals held positions at the center, a few dozen directors served on a large number of boards, and thus the distance between any two companies or directors was short—has largely collapsed during the past decade. There is no longer a stable core of companies that reliably occupies a center, and the mean geodesic has gone up continuously since 2002. The proximal cause is that no cohort of super-connector directors has arisen to take the place of those who have retired. This contrasts with prior generations, in which ambitious individuals sought out multiple board seats for the benefits they provided in status, business connections, and monetary compensation. We speculate that the Sarbanes-Oxley Act, along with other corporate governance reforms, has made serving on several boards costly, resulting in the decline in one of sociology’s most-studied networks.

Scale-free dynamics in physical and biological systems can arise from a variety of causes. Here, we explore a branching process which leads to such dynamics. We find conditions for the appearance of power laws and study quantitatively what happens to these power laws when such conditions are violated. From a branching process model, we predict the behavior of two systems which seem to exhibit near scale-free behavior-rank-frequency distributions of number of subtaxa in biology, and abundance distributions of genotypes in an artificial life system. In the light of these, we discuss distributions of avalanche sizes in the Bak-Tang-Wiesenfeld sandpile model.

We observe the propagation of information in a system of self-replicating strings of code (``Artificial Life'') as a function of fitness and mutation rate. Comparison with theoretical predictions based on the reaction-diffusion equation shows that the response of the artificial system to fluctuations (\eg velocity of the information wave as a function of relative fitness) closely follows that of natural systems. We find that the relaxation time of the system depends on the speed of propagation of information and the size of the system. This analysis offers the possibility of determining the minimal system size for observation of non-equilibrium effects at fixed mutation rate.