Abstract: A model in which a manufacturer sells products through an e-commerce platform and a traditional offline retailer is constructed.Specifically,the e-commerce platform selects online selling format and establishes information sharing strategy.This paper compares and analyses four situations where the online selling format is either reselling or agency selling with or without information sharing.Based on Bayesian game and information leakage effect,what is the e-commerce platform's choice,agency selling or reselling with the interaction of information investing cost and sharing strategy in dual-channel supply chain.Research shows that,firstly,unless the demand uncertainty is low and the platform revenue sharing ratio is high,the e-commerce platform selects the reselling format.Secondly,the e-commerce platform's incentive to share information strongly depends on its online selling format selection and demand uncertain degree.Under reselling case,the e-commerce platform does not share information voluntarily.While under agency selling case,the e-commerce platform shares information with manufacturer voluntarily when the demand uncertainty is high.Finally,under agency selling case,information sharing is beneficial for all members of supply chain.More specially,information sharing is not always beneficial for the entire dual-supply chain under reselling case.Only if the demand uncertainty is high and the cross-channel substitutability is small,information sharing can improve the performance of entire supply chain.

Key words: Bayesian game, E-commerce platform, Information leakage, Information sharing