From Mass to Motion: Conceptualizing and Measuring the Temporal Dynamics of Industry Clusters

Abstract

This article outlines a temporal dynamics approach to the study of industry clusters. Despite extensive work on cluster size (or “mass”), little attention has been paid to their temporal dynamics (or “motion”). We propose that understanding cluster dynamics is important, because clusters are seldom stable, and cluster dynamics may have strategic implications not accounted for by existing approaches. We introduce a novel measure of cluster motion. Applying this measure to data on establishments in the U.S. computer and semiconductor industries, we document wide variation in cluster mass over time, both within and across regions. Furthermore, utilizing patent data, we find that cluster motion correlates with localized knowledge spillovers in ways different from cluster mass, suggesting that our approach may offer novel insights to strategy researchers.