Modern Theory of Rent This theory is also known as demand and supply theory of land. It is based on the following assumptions: 1. There is always perfect competition among various cultivations. 2. The fertility of different lands is same. 3. The land is used for a particular job. Explanation of the Theory The theory explains the concept of rent in terms of demand and supply. According to the theory rent is payment for the use of land. Demand for the use of land is actually the demand for that product which is produced on it. Demand for the land will increase with increase in demand for that particular product. Since th supply of land is fixed i.e. The supply cannot increase or decrease therefore the rise or fall of rent will be entirely governed by it’s demand. Thus on the side of demand rent of land is determined by its productivity not total productivity, but marginal productivity. And for supply, the supply of land in general is absolutely inelastic, as such in supply is independent of what it earns. From the following figure it is clear that the supply of land is fixed SS, while as demand is increasing from DD to D’D’ and to D’’ to D’’, the rent is also increasing from RR to R’R’ and to R’’R’’. Answered by kishor BVIMED