Bilevel Programming Model for Optimal Number and Scale of Coal Mining Companies

A bilevel programming is proposed to research the relation between number and scale of coal mining companies. To optimize resources, the upper level decision maker(social regulation) chooses the number of coal mining companies to minimize social average cost and maximize social average benefit, and the lower level decision makers(coal mining companies) optimize their scales to maximize benefit. According to the solution of the model, the results are analyzed when the social regulation have different reference to the social average cost and social average benefit. After that some conclusions are narrated for social regulation and coal mining companies´ decisions.