Learning by Drilling: Interfirm Learning and Relationship Persistence in the Texas Oilpatch *

This article examines learning-by-doing that is specific not just to individual firms but to pairs of firms working together in a contracting relationship. Using data from the oil and gas industry, I find that the productivity of an oil production company and its drilling contractor increases with their joint experience. This learning is relationship-specific: drilling rigs cannot fully appropriate the productivity gains acquired through experience with one production company to their work for another.This result is robust to ex ante match specificities. Moreover, producers' and rigs'contracting behavior is consistent with maximization of relationship-specific learning's productivity benefits.