A monopolized market can be more conducive to invention than a competitive market in contrast to Arrow's assertion of the opposite. Monopoly stimulates inventive activities relative to competition if the securing of an innovation permits the inventor to enter the market in either case. Under quite general conditions, an entrant into a monopolized market can capture some of the existing monopoly rents, which are not present in a competitive market. The prospect of acquiring some of these rents in the monopoly case provides the additional incentive, leading to increased inventive efforts.