How Wide is the Scope of Hold-Up-Based Theories? Contractual Form and Market Thickness in Trucking

How far do the contractual implications of hold-up-based theories (Klein, Crawford, and Alchian (1978), Williamson (1979, 1985)) extend? I investigate this in the context of trucking. Quasi-rents in trucking are generally smaller than in the contexts studied in the previous empirical literature. They vary with hauls' distance and the thickness of local markets. I find that doubling the thickness of the market increases the likelihood that simple spot arrangements govern transactions by about 30% for long hauls. I find weaker evidence of relationships between local market thickness and contractual form for short hauls -- hauls for which quasi-rents are particularly small. Contracts' role as protectors of quasi-rents becomes less important as quasi-rents decrease, but exists over a surprisingly large range.