The demand for apartments in the low-income area would be relatively inelastic due to lack of substitutes and high rents as a proportion of income. The supply of apartments would also be relatively inelastic given the lack of available land and low returns from building in the area. A rent supplement program that pays part of rents would shift demand right, increasing rents and benefiting landlords more than renters. A building subsidy program would shift supply right, lowering rents and benefiting renters more than landlords. Overall, the building subsidy program better achieves the goal of improving housing for the poor.