信用卡、风险应对与城镇家庭股市参与

信用卡市场的发展有利于家庭平滑消费,但是否会影响家庭的投资决策尚缺少事实检验。基于中国家庭金融调查(CHFS)2011和2013年的调查数据,本文首次检验了信用卡对城镇家庭股市投资的影响。研究发现:(1)控制家庭财富、融资渠道、社会资本等特征,持有信用卡在边际上促进了家庭的股市参与率,股市投资额取决于信用额度。(2)中国信用卡市场的发展,并未像流动性约束理论预测的可以平滑消费,反而刺激了家庭风险性资产的配置,最终提高了储蓄率。原因在于,中国家庭更多地将信用卡作为应对未来短期突发性风险的金融工具,从而在当期将更多资产配置在风险资产上,以实现资本积累。使用信用卡数目、信用额度等多种衡量方式,并采用工具变量法(IV)和面板数据固定效应模型等解决内生性问题后,该结论稳健。该研究有助于理解信用卡在中国家庭投资决策的作用,并为流动性约束或有限股市参与假说提供中国经验。

Credit Cards,Risk Coping,and Stock Market Participation in Urban Households

According to the precautionary savings or liquidity constraints theory, households with liquidity constraints will use savings to cope with risk. The emergence of credit cards has reduced liquidity constraints and consequently improved household consumption. Based on the household choice to consume, save, or invest, the development of credit cards is likely to affect investment decisions. However, few studies have explored this effect.
According to the Chinese Household Finance Survey (CHFS) data for 2013, the percentage of urban households in China with credit cards surged from 0.5 percent in 2000 to 24 percent in 2012. Meanwhile, the percentage of households participating in the stock market rose from less than 1 percent in 2000 to 11.5 percent in 2012, showing the same upward trend as the credit card market. Theoretically, there are two possible channels: first, credit cards can reduce liquidity constraints, and second, they can be considered as financial tools for coping with risk. This study uses Chinese household microdata to investigate the relationship between credit cards and household investment, including the mechanisms behind this effect. It contributes to our understanding about the effect of credit card markets development in China on household investment decisions, and it reveals empirical evidence for the hypothesis of liquidity constraints and limited stock participation.
The Chinese Household Finance Survey (CHFS) was conducted by Southwestern University of Finance and Economics in China. It provides representative financial panel data at the household and individual level, including financial and non-financial assets, liabilities, credit cards, credit constraints, income, consumption, demographic characteristics, and payment habits. This comprehensive and systematic household panel survey focused on the Chinese financial system and covered 8,438 households in 2011 and 28,143 during the second wave in 2013. Among these samples, 6,847 households could be followed up, comprising 66.7 percent of urban households.
This study conducts an empirical analysis using not only cross-sectional pool data but also panel data that could be followed up. The findings are as follows. First, credit card holders in urban China are more likely than non-holders to participate in the stock market. The total investment value also increases with the enhancement of the credit line. Second, the credit card is considered to be a financial tool for coping with short-term income risk. By keeping consumption level constant, households can allocate more to stock assets instead of holding cash and fixed savings deposits. This study also finds that the more credit cards households hold, the more they participate in the stock market, and the investment value in the stock market depends mainly on the credit line.
To avoid measurement errors generated by reverse causality and omitted variables, we apply the instrumental variable method of estimation using the 2SLS-Probilt model. Specifically, the instrumental variable of whether the household holds a credit card is measured by whether there are promotions in the household's community. To exclude the impact of omitted variables, we perform numerous robustness checks, including applying the fixed effect model using panel data that could be followed from 2011 to 2013. Furthermore, we use relatively exogenous proxy variables such as the number of credit cards and the credit line to estimate the effect of credit cards on stock market investment. In addition to proxy variables, we consider the sequence of credit card holding and stock holding to avoid reverse causality problems. The results of these variant methods all support our conclusion.
Although there is international empirical evidence that credit cards can boost consumption, consistent with the prediction of precautionary savings theory, the development of the Chinese credit card market has not reduced the household savings rate or increased consumption as previously concluded. On the contrary, Chinese households prefer to use credit cards as financing tools to respond to short-term income risks, and increase risky investments by cutting back non-risk assets (cash or fixed deposits) with little reduction in savings on average. To sum up, further research is needed to establish whether the development of credit cards enhances consumption or investment.