Product innovation with vertical differentiation: Is a monopolist's incentive weaker?

This paper compares the incentives for product innovation across different market structures when the new product is vertically differentiated and of lower quality, a common case empirically. We show that innovation incentive rankings across market structures can differ substantially when the new product is of lower rather than higher quality. In particular, the incentive to add the new product can be greater for a monopolist over the old product than for a firm that would face any degree of competition from the old product. This incentive ranking cannot occur when, instead, the new product is of higher quality as has been analyzed in previous work. Moreover, in that case, the incentive ranking is the same whether the market is covered or not covered, whereas in our setting the ranking can differ. With the market covered, our setting provides another environment where the monopolist can have the greatest incentive to innovate, as previously shown when the new product is horizontally differentiated. Together, both settings show that Arrow's famous result—a secure monopolist gains less from a nondrastic process innovation than would a competitive firm—does not always extend to nondrastic product innovations. However, in all the cases analyzed here, consumer welfare (though not total welfare) is always lower under monopoly, even when only the monopolist would add the new product.