In the United States, the costs of unionized labor are higher in states without right-towork (RTW) laws. I show that unionized firms located in these states invest less. These firms have about 4 percentage point lower capital expenditures (normalized by net property, plant, and equipment) than other firms. I confirm these findings by examining a natural experiment created by the adoption of RTW laws in Oklahoma and examining union certification elections using regression discontinuity design.