Telecommunications and Travel: The Case for Complementarity

This article examines the conceptual, theoretical, and empirical evidence with respect to the impact of telecommunications on travel. The primary focus is on passenger travel, but goods movement is addressed briefly. I argue that although direct, short‐term studies focusing on a single application (such as telecommuting) have often found substitution effects, such studies are likely to miss the more subtle, indirect, and longer‐term complementarity effects that are typically observed in more comprehensive analyses. Overall, substitution, complementarity, modification, and neutrality within and across communication modes are all happening simultaneously. The net outcome of these partially counteracting effects, if current trends continue, is likely to be faster growth in telecommunications than in travel, resulting in an increasing share of interactions falling to telecommunications, but with continued growth in travel in absolute terms. The empirical evidence to date is quite limited in its ability to assess the extent of true causality between telecommunications and travel, and more research is needed in that area. At this point, what we can say with confidence is that the empirical evidence for net complementarity is substantial, although not definitive, and the empirical evidence for net substitution appears to be virtually nonexistent.