Innovation, competition and firm size distribution on fragmented markets

This paper presents a simple model of firm and consumer behavior. We formulate a sub-market entry game, where boundedly rational firms decide on investing in R&D for inventing new products that will appeal to targeted groups of consumers. The success depends on the amount of resources available for the project as well as on the firm’s familiarity with market characteristics. Successful innovation feeds back into the firm size and (potentially into) market knowledge and increases the future R&D productivity. A new product decreases the market-shares of incumbents. However, this business stealing effect is asymmetric across incumbent population. We identify the section of parameter space where firms have an incentive to diversify horizontally. In this section, the model results in rich industrial dynamics. Firm size heterogeneity emerges endogenously in the model. Equilibrium firm size distributions are heavy tailed and skewed to the right. The heaviness of the tail depends on submarket specificity of firm’s market knowledge. This relationship is non-monotonic, emphasizing two different effects of innovation on industrial dynamics (positive feedback and asymmetric business stealing).