  Most businesses impose a supervisory hierarchy on employees to facilitate
management, decision-making, and collaboration, yet routine inter-employee
communication patterns within workplaces tend to emerge more naturally as a
consequence of both supervisory relationships and the needs of the
organization. What then is the relationship between a formal organizational
structure and the emergent communications between its employees? Understanding
the nature of this relationship is critical for the successful management of an
organization. While scholars of organizational management have proposed
theories relating organizational trees to communication dynamics, and
separately, network scientists have studied the topological structure of
communication patterns in different types of organizations, existing empirical
analyses are both lacking in representativeness and limited in size. In fact,
much of the methodology used to study the relationship between organizational
hierarchy and communication patterns comes from analyses of the Enron email
corpus, reflecting a uniquely dysfunctional corporate environment. In this
paper, we develop new methodology for assessing the relationship between
organizational hierarchy and communication dynamics and apply it to Microsoft
Corporation, currently the highest valued company in the world, consisting of
approximately 200,000 employees divided into 88 teams. This reveals distinct
communication network structures within and between teams. We then characterize
the relationship of routine employee communication patterns to these team
supervisory hierarchies, while empirically evaluating several theories of
organizational management and performance. To do so, we propose new measures of
communication reciprocity and new shortest-path distances for trees to track
the frequency of messages passed up, down, and across the organizational
hierarchy.
