Abstract: With the popularity of internet transactions, more and more enterprises and individuals have taken the internet market as an important channel for product purchase and sale. The increase in the volume of online shopping has not only promoted the prosperity of the e-commerce platform market, but also brought great pressure to the smooth logistics. Logistics timeliness is considered as the decisive variable affecting buyer′s online shopping and logistics costs. The paper constructs two different decision-making game models of the e-commerce platform market based on the buyer′s demand function affected by linear and non-linear logistics timeliness, solving and comparing the equilibrium of the decisions and income of the participants of the e-commerce platform market, such as e-commerce platform company, the online seller, the online buyer and the logistics express enterprise. The results show that the stronger the basic demand of buyer′s online shopping, the more likely the buyer′s demand function for logistics timeliness is linear, so under this circumstance, the prices of the platform, the online seller and the logistics provider are lower, while the buyer′s purchase quantity is higher, and the equilibrium returns of all parties are higher than those of nonlinear scenarios;on the contrary, when the buyer′s basic demand for online shopping is weaker, the more likely the buyer′s demand function for logistics timeliness is nonlinear, so under this circumstance, the prices of the platform, the online seller and the logistics provider are lower, while the buyer′s purchase quantity is higher, and the equilibrium returns of all parties are higher than those of linear scenarios. The decision equilibrium of the two different kinds of demand function can provide some reference for the platform, the online seller and the logistics express enterprise to quickly identify the buyer′s demand type and realize the rationality of their price decisions, and then optimize their profit margins.

Key words: online shopping, logistics timeliness, linear demand, nonlinear demand, e-commerce platform, game, equilibrium