Using Military Troop Movements to Estimate the Effect of Employment Growth on Travel Time To Work

• Environmental and Resource Economics Workshop

Date and Location

Friday, November 30, 2012, 12:10 PM - 1:30 PM
ARE Conference Room, 2102 Social Sciences and Humanities

Abstract

We examine how rapid and unanticipated spikes in employment affect a region’s travel time to work using movements of military troops during the 2005 Base Realignment and Closure (BRAC) process. Anecdotal media reports suggest traffic congestion increased substantially due to these troop movements. The BRAC process provides a convenient quasi-experimental framework to measure this effect because it occurred exogenous to the normal transportation planning process. Using difference-in-difference, difference-in-difference-in-difference, and instrumental variable methods we demonstrate that the effect of unanticipated employment growth is between 0.0032-0.0550 of additional minutes of travel time for every additional commuter added per square kilometer. We also estimate the economic travel time cost to regions when rapid employment growth occurs and find that the 2005 BRAC cost between $155 million and $1.5 billion in added travel time per year.