The first theoretical works on labor-contract length, Gray (1978) for example, emphasized the existence of a negative relation between contract duration and uncertainty. In estimating a linear version of Gray's contract-length model and an alternative model developed by Christofides and Wilton, our empirical results indicate little evidence of a negative relationship between length and uncertainty in the United States. Furthermore, our findings indicate the presence of significant differences across industries (at the two-digit SIC level) in the response of bargain duration to uncertainty. © 1991.