Adverse selection remains a significant challenge in the insurance industry, often resulting in substantial financial losses for insurers. The primary hurdle in addressing the issue lies in accurately identifying and quantifying adverse selection. Traditional methods often fail to adequately account for the heterogeneity of insurance purchasers and the endogenous nature of their insurance decisions. This study introduces an innovative approach that integrates the Gaussian Mixture Model and the regression-based model from Dionne et al. (2001) to assess adverse selection, addressing the limitations of previous methods. Through comprehensive simulations, we demonstrate that our method yields unbiased estimates, outperforming existing approaches. Applied to China’s automobile insurance market, leveraging IoT devices to track telematics data, this method captures risk heterogeneity among the insured. The results offer robust evidence of adverse selection, in contrast to conventional methods that fail to detect this phenomenon due to their inability to capture the underlying relationship between customer risk and claim behavior. Our approach offers insurers a robust framework for identifying information asymmetries in the market, thereby enabling the development of more targeted policy interventions and risk management strategies.

The study finds that analyst skill plays a key factor to explain the complicated and chaotic relation between analyst coverage and external governance. We divide analysts into multiple skill groups by GMM (Gaussian mixture model) method, and explore the effect of the coverage by skilled analysts on earnings management in Chinese listed companies. The results indicate that only the coverage of skilled analysts shows a significant negative correlation with earnings management. Heterogeneity analysis reveals that the negative relationship between the coverage of skilled analysts and earnings management is primarily observed in non-state-owned companies, those with weaker external audits, and smaller-scale firms. The conclusion remains robust after considering endogeneity issues. The findings of this study suggest that incorporating analyst skill contributes to a better understanding of the mechanisms through which analysts influence corporate governance. It also highlights that the role of analysts in corporate governance cannot be generalized.