عنوان مقاله [English]
Objective: Information asymmetry and its problems are one of the most important issues in the insurance industry. Asymmetric information between insurer and insured can severely affect insurance companies' profit and pose significant risks to them. One of the most important risks arising from asymmetric information is adverse selection risk. Adverse selection is the tendency of high risks to be more likely to buy insurance or to buy larger amounts than low risks. Adverse selection is an important source of inefficiency in insurance markets. In this regard, the main purpose of this study is to investigate the risk of adverse selection in Iran's health insurance industry.
Methodology: In this study we use a model of demand for health services to incorporate the essential features of asymmetric information in health insurance markets. This model is based on the work of Bajari et al. (2014) and Culter & Zeckhauser (2000). The used data is extracted from the cost and income inventory of the urban and rural households in Iran in 2016. In order to test the existence of adverse selection in the Iranian health insurance industry, at the first step, using the nonlinear least squares (NLS) method the demand function for health services is estimated, and employing the estimated parameters, the latent health status variable of each household is obtained. Afterwards, the latent health status distribution between the two groups of insured and uninsured households are compared using Kolmogorov-Smirnov statistic test.
Findings: The result of the two-sample Kolmogorov–Smirnov test shows that the distribution of latent health variable is not equal in two groups of insured and uninsured households. In other words, there is a significant difference between the health status of insured and uninsured households. As well as, a comparison of the distribution of latent health status between insured and uninsured households shows that on average the level of latent health of insured households is lower than that of uninsured households. Therefore, existence of adverse selection in the Iranian insurance industry is confirmed. Also, according to the results, the risk aversion parameter of households for consumption of health services ( ) equals to 0.1109 and for consumption of other goods ( ) is equal to 0.0226. This result implies that households are more risk averse with respect to health status than to the aggregate consumption commodity.
Conclusion: The results confirm the existence of adverse selection in the Iranian health insurance industry. In addition, the results show that risk aversion for the consuming health services is higher than other goods consumption. Therefore, it is essential that health insurance companies plan and act to reduce the risk of adverse selection. We also presented some strategies to minimize the adverse selection risk.
JEL Classification: I11, I13, C14.