Abstract: | This paper examines the spillover and competition effects of corporate social responsibility (CSR) with duopoly competition. In employing the assumption that firm CSR increases consumer willingness to pay for the firm's products while consumer willingness to pay decreases for non‐CSR firm products, some interesting conclusions are achieved. First, CSR spillover effects increase CSR firm outputs and prices, while CSR spillover has the opposite effect on competitors. Second, CSR spillover decreases total outputs and total social welfare levels. Third, competition effects increase CSR expenditures, and CSR firms' CSR policies are the most robust when non‐CSR firms assume a leading position. It is found that total outputs and consumer utilities are highest when CSR firm acts as leader, while the relationships of social welfare among different cases are ambiguous depending on product substitution and spillover effects. |