Before revision:  The mean integrated squared error for the density estimator of a random variable in \mathbb{R the  California Department of Transportation to explore whether their choice of awarding construction contracts using a first price auction is cost minimizing  .
After revision:  The mean integrated squared error for the density estimator of a random variable in \mathbb{R the California Department of Transportation to explore whether their choice of awarding construction contracts using a first price auction is cost minimizing . We estimate the marginal costs of construction firms subject to Myerson's (1981) regularity condition, which is a requirement for the first price reverse auction to be cost minimizing. The proposed test fails to reject that the regularity condition is satisfied .