房地产市场、家庭杠杆率与消费——一个异质性代理人模型

Housing Market, Household Leverage Ratio and Consumption: A Heterogeneous Agent Model

近年来,中国消费增速持续下降,而同期家庭部门杠杆率却持续攀升,特别是在房地产市场繁荣期,这种反向关系表现的更加突出。那么,家庭杠杆的增加是否是消费不振的动因?其作用机制是什么?本文的经验证据显示:家庭通过增加了与住房债务相关的杠杆,挤出了流动性,从而减少了消费。并且在房地产政策刺激之后,购买非首套房的家庭消费的平均下降程度显著高于购买首套房的家庭,这意味着投机性的购房动机可能发挥了作用。为了阐释经验发现的机制,本文构建了异质性代理人模型,从理论上区分了家庭“刚需”和“投机”购房动机的决策差异,发现对房价大幅上涨的预期会引发部分非首套房家庭的“投机”购房动机,促使他们极致的加杠杆并大量消耗流动性,从而大幅挤出消费。因此,可以通过流动性特征识别购房动机、细化首付比调控政策以减少投机,并通过舆论引导、优化“三道红线”和房贷本息支付政策,实现在“房住不炒”总方针下的“稳房价、稳预期和提消费”。

According to statistical data,China’s consumption has been in a relative downturn in recent years,and while the growth rate of consumption has continued to fall,the leverage ratio of the household sector has been rising year on year.This inverse relationship was particularly prominent after the introduction of China’s strong housing stimulus on September 30,2014:the accelerated climb in household sector leverage was accompanied by a marked acceleration in the downward trend in the growth rate of consumption.So,is the increase in household leverage a driver of sluggish consumption?What are the mechanisms behind the emergence of this phenomenon?Answering these questions is important for unblocking the domestic circulation in China and activating the sustained engine of economic development.First of all,this paper uses data from the China Household Finance Survey from 2011 to 2017 to verify the dampening effect of increasing household leverage on consumption:for every 100%increase in household leverage,consumption falls by an average of 1.8%.Further empirical analysis finds that only the leverage climb associated with housing debt depresses household consumption,and that this effect works by crowding out households’liquidity.Finally,this paper uses the PSM-DID approach to estimate the difference in the impact of China’s housing stimulus on September 30,2014 on the consumption of different house-buying households.It finds that households that use leverage to buy a non-first house experienced a significantly higher decline in consumption than those that bought a first,implying that differences in house-purchase motivation of households may be playing a role.In order to shed more light on the underlying mechanisms behind the empirical evidence,this paper builds a heterogeneous agent model for the household sector,innovatively incorporating differences in households’decisions between the rigid and speculative motivations to purchase a house,and thus incorporating the China-specific issue of whether to purchase a first or a non-first house into the analytical framework.The model simulates the stimulus effect of China’s strong housing stimulus on September 30,2014,which reduced the minimum down payment ratio for second house purchase from 70%to 40%,and households simultaneously formed optimistic expectations of rising house prices.It is found that the policy stimulus led households to expect a sharp rise in house prices,triggering a speculative motivation for some non-first homebuyers,leading to a significant increase in their leverage and crowding out consumption through the liquidity channel.Furthermore,by comparing the change before and after the purchase of a house between households in rigid need and those with speculative incentive,we find that speculative households tend to consume more liquidity and extremely use leverage to reach the threshold of house-buying,thus reducing their consumption much more than other types of households.Based on this analysis,this paper argues that in the current condition of China,in order to effectively boost consumption under the policy of“houses are for living in,not for speculation”,we can first identify the demand of homebuyers by setting up bank mortgage conditions with liquidity clauses,and refine the down payment ratio regulation policy to achieve the purpose of reducing speculation and preventing a further decline in consumption growth.Then,we further stabilize public expectations of property prices by combating the“collusion”of speculative homebuyers and housing agencies,building a public opinion guidance system,curbing land premiums and strictly regulating the operation of housing enterprises.Finally,the policy on the payment of principal and interest on household mortgages should be optimized according to the actual situation,so as to ease the debt servicing burden of households and reverse the current downturn in consumption.