sentences:  Although later used in the context of urban analysis, though not yet using this term, the bid rent theory was first developed in an agricultural context.One of the first theoreticians of bid rent effects was David Ricardo, according to whom the rent on the most productive land is based on its advantage over the least productive, the competition among farmers ensuring that the full advantages go to the landlords in the form of rent.This theory was later developed by J. H. von Thünen, who combined it with the notion of transport costs.