Predictors of short-term decay of cell phone contacts in a large scale communication network

Under what conditions is an edge present in a social network at time t likely to decay or persist by some future time t + Δt? Previous research addressing this issue suggests that the network range of the people involved in the edge, the extent to which the edge is embedded in a surrounding structure, and the age of the edge all play a role in edge decay. This paper uses weighted data from a large-scale social network built from cell-phone calls in an 8-week period to determine the importance of edge weight for the decay/persistence process. In particular, we study the relative predictive power of directed weight, embeddedness, newness, and range (measured as outdegree) with respect to edge decay and assess the effectiveness with which a simple decision tree and logistic regression classifier can accurately predict whether an edge that was active in one time period continues to be so in a future time period. We find that directed edge weight, weighted reciprocity and time-dependent measures of edge longevity are highly predictive of whether we classify an edge as persistent or decayed, relative to the other types of factors at the dyad and neighborhood level.     

Understanding the Elusive Black Box of Dynamic Capabilities

A major challenge for managers in turbulent environments is to make sound decisions quickly. Dynamic capabilities have been proposed as a means for addressing turbulent environments by helping managers extend, modify, and reconfigure existing operational capabilities into new ones that better match the environment. However, because dynamic capabilities have been viewed as an elusive black box, it is difficult for managers to make sound decisions in turbulent environments if they cannot effectively measure dynamic capabilities. Therefore, we first seek to propose a measurable model of dynamic capabilities by conceptualizing, operationalizing, and measuring dynamic capabilities. Specifically, drawing upon the dynamic capabilities literature, we identify a set of capabilities—sensing the environment, learning, coordinating, and integrating—that help reconfigure existing operational capabilities into new ones that better match the environment. Second, we propose a structural model where dynamic capabilities influence performance by reconfiguring existing operational capabilities in the context of new product development (NPD). Data from 180 NPD units support both the measurable model of dynamic capabilities and also the structural model by which dynamic capabilities influence performance in NPD by reconfiguring operational capabilities, particularly in higher levels of environmental turbulence. The study's implications for managerial decision making in turbulent environments by capturing the elusive black box of dynamic capabilities are discussed.     

Kernel Method Starting with Half-Normal Detection Function for Line Transect Density Estimation

In this article, we introduce the nonparametric kernel method starting with half-normal detection function using line transect sampling. The new method improves bias from O(h ²), as the smoothing parameter h → 0, to O(h ³) and in some cases to O(h ⁴). Properties of the proposed estimator are derived and an expression for the asymptotic mean square error (AMSE) of the estimator is given. Minimization of the AMSE leads to an explicit formula for an optimal choice of the smoothing parameter. Small-sample properties of the estimator are investigated and compared with the traditional kernel estimator by using simulation technique. A numerical results show that improvements over the traditional kernel estimator often can be realized even when the true detection function is far from the half-normal detection function.     

Organizations and the structure of culture

Recent work emphasizes how organizations and organizing are suffused by culture. Ignored, however, is the question of how organizations and organizing shape cultural understandings. In this paper, we draw attention to how organizations impact the creation, maintenance, and matching of cultural associations: The “structure of culture.” Cultural associations are distributed understandings of “what goes with what,” diffused via their co-adoption by individual and corporate actors. We argue that the process of associative diffusion is heavily influenced by organizational forms, routines, and operations. While organizations shape culture production, they likewise shape resulting associations between cultural items, actively modifying the structure of culture. We conclude that the role of organizations in shaping the structure and dynamics of culture should be a central topic of study moving forward.     

A Motivational Theory of Roles,Rewards, and Institutions

In this paper, we attempt to rehabilitate the notion of role by linking sociological role theory to recent work on motivational, affective, and cognitive neuroscience specifying the internal mechanisms behind motivated action. We argue that there is nothing inherently problematic or retrogressive in the idea of “role,” once its link to a purely normative account of motivated action is severed. Instead, by conceptualizing roles as emerging and persisting around structured reward systems, we are able to incorporate contemporary motivational science such that rewards become the proximate causal mechanisms currently missing in role theory. Consequently, a key implication of our argument is that the best way to link role, action, and structures is by reviving the idea of institutions as literal reward systems, which allows us to envision roles as the mechanisms via which the pursuit and delivery of rewards and goal-objects are routinized. Implications for a motivational theory of roles, rewards, and institutions is discussed.