Effects of Motor Carriers' Growth or Contraction on Safety: A Multiyear Panel Analysis

Motor carrier safety remains a highly relevant issue for supply chain managers and scholars because carriers' safety affects supply chains as well as the welfare of the motoring public. This article enriches understanding regarding this topic by investigating how motor carriers' growth or contraction since the start of the Compliance, Safety, and Accountability (CSA) program in 2010 affects their safety performance. Drawing on core principles from theories regarding internal adjustment costs from economics and nonscale free capabilities from management, we explain why carriers' growth or contraction should differentially affect various safety metrics tracked by the CSA program. To test our theory, we assemble a multiyear panel data set for over 1,000 of the largest for-hire motor carriers operating in the United States by melding together several different governmental data sources. We fit a series of multivariate seemingly unrelated regression models to test our hypothesized effects. Our results corroborate our theorized predictions and are robust to alternative model specifications. We conclude by detailing how this work contributes to extant theory, summarizing managerial and policy implications, highlighting limitations, and suggesting directions for further pursuit.