Abstract: From the perspective of supply chain members considering investing in corporate social responsibility (CSR), this paper constructs six closed-loop supply chain ( CLSC) decision models under concentration mode and decentralization mode respectively and in three scenarios: no CSR investment, CSR investment by manufacturers and CSR investment by retailers; the influence of CSR investment and recycling competition of supply chain members on equilibrium strategy and profits under different decision models are analyzed; then taking the CSR investment by manufacturers as an example, the feasibility of various coordination strategies is discussed. The research findings are as follow. Firstly, the retail price and market demand of new products, the recycling rate of waste products and the profits of CLSC members and the whole system are positively correlated with CSR investment and negatively correlated with the degree of recycling competition. Secondly, economic efficiency and sustainable development benefit more from retailers’ CSR investment than from manufacturers’ CSR investment. Finally, a review of the relevant contracts shows that, although the price contract based on cost sharing can achieve the overall coordination of CLSC, it cannot improve the profits of manufacturers and retailers at the same time, so it cannot be implemented, and the price contract based on revenue sharing or with fixed subsidies can achieve the coordination of supply chain members and the whole system simultaneously.

Key words: closed-loop supply chain, dual-channel recycling, CSR investment, pricing decision, coordination strategy