中文摘要
近几十年来, 房价相对收入大幅上涨, 使住房越来越难以负担。我们构建并量化了一个分割住房市场模型, 以研究住房成本上升的驱动因素, 并评估旨在遏制这些成本的政策。我们表明, 财富离散度的上升加之住房供给停滞, 可以解释所观察到的住房成本上升。首付援助和抵押贷款利息扣除等需求侧政策会在无意中给房价带来上行压力, 加剧住房不可负担性。可负担住房开发或建设的税收抵免等供给侧政策则通过增加住房存量来降低房价。新建住房的类型很重要: 与低端细分市场的新建住房相比, 高端细分市场的新建住房对住房市场所有细分领域可负担性的改善作用更大。
Abstract
Recent decades have seen house prices grow strongly relative to incomes, making housing ever less affordable. We develop and quantify a model of segmented housing markets to study the drivers of rising housing costs and to evaluate policies aimed at curbing these costs. We show that rising wealth dispersion, together with stagnating housing supply, can explain the observed increase in housing costs. Demand-side policies such as down payment assistance and mortgage interest deductions inadvertently cause upward pressure on house prices and exacerbate unaffordability. Supply-side policies such as tax credits for development or construction of affordable housing lower house prices by increasing the housing stock. Which type of new housing is built matters: new construction in the high-end segments improves affordability by more in all segments of the housing market compared to new construction in bottom-end segments.