In contrast, Paluzie (2001) and Monfort & Nicolini (2000) extend the original Krugman model
by assuming that labor is not internally mobile, and show that trade agreements can increase agglomeration
within the country, since as trade in manufacturing increases, regions already with these
manufacturing facilities (i.e. maquiladora hubs in the north of Mexico) will tend to benefit more than
other regions. The core differences between the Paluzie and Krugman models are, first, Paluzie (2001)
assumes that high land costs and rents are the centrifugal force encouraging dispersion instead of the
demand of dispersed agricultural population. Second, she assumes labor is immobile in the short run.
The result is that once trade is opened up, imports and exports to and from the major cities increase
more than the demand from rural areas (Rodr´ıguez-Pose & Gill 2006).