Des services de transport de qualité apportent beaucoup à la productivité d’une économie et élargissent l’éventail des activités accessibles aux consommateurs. Ils requièrent des infrastructures adéquates et des conditions raisonnables d’utilisation de ces infrastructures....

Good transport services contribute strongly to the productivity of an economy and extend the range of activities accessible to consumers. Good services require adequate infrastructure and reasonable usage conditions to that infrastructure. Much transport infrastructure is capital intensive and...

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...