Back to the future to improve U.S. transportation -- Intercity transportation under partial deregulation -- Highways -- Urban transit -- Airports and air traffic control -- Constraints on efficient reforms -- Lessons from deregulation of intercity transportation -- Theory and evidence on the...

We investigate biofuel substitution in the U.S. transportation sector, for the period from 1990 to 2017, using the normalized quadratic model. We relax the homoskedasticity assumption and instead assume that the covariance matrix of the errors of the flexible demand system is time-varying. We...