US has about 200 cities which have some sort of rent control system and is more common in states of New Jersey, California and New York, many states have eliminated the rent control system altogether. However, studies conducted on the New Jersey rent control policies shows that implementing rent control increases the supply of rental houses as there is incentive for the landlords who feel motivate to subdivide there larger rental units. A more recent on the San Francisco housing markets indicates rental control had no effect on the decrease of new