To date, empirical investigations of trade liberalization under the conditions of increasing returns to scale (IRS) and imperfect competition (IC) have either assumed or imposed the market and productive structures necessary for such a model. However, of the recent IRS/IC models used to simulate...

Rail cost function analysis has been a popular topic in the (empirical) economics literature over the past decades. Most studies find increasing returns to density for rail companies. The results can, however, be quite diverse. Results for the Dutch National Railway company (NS), for instance,...