“…These factors are: i) population; ii) income; iii) transportation costs and iv) agricultural rent (Burchfield et al, 2006;McGibany, 2004;McGrath, 2005;Song & Zenou, 2006;Wassmer, 2002Wassmer, , 2006Wassmer, , 2008. 3 The present study concentrates on natural evolution factors, particularly the private transportation cost of individuals.…”