Sunk Costs, Market Structure, and Growth
构建了一个内生创新模型，企业进行内部研发，研发支出作为固定成本影响企业数量，进而决定增长率和市场结构，存在多重均衡且企业竞争预期影响经济表现。
The author presents a model of endogenous innovation where firms undertake in-house research and development (R&D). The concentration of sales and R&D resources determines the scale and efficiency of R&D operations and rate of productivity growth. In zero-profit equilibrium, R&D expenditure is one component of total fixed costs and determines the number of active firms. This feedback generates interdependent pricing, investment, and entry/exit decisions. The (jointly determined) rate of growth and number of firms supported in general equilibrium define the economy's balanced growth path. Multiple equilibria exist, and firms' expectations about rivalry determine the economy's performance. Copyright 1996 by Economics Department of the University of Pennsylvania and the Osaka University Institute of Social and Economic Research Association.