In the 1990s‎,‎ growth theory has incorporated imperfect competition in its investigations‎.‎ This innovation has proven to be seminal‎:‎ Cleviating from growth models with perfect competition‎,‎ the new framework featured forward‎- looking entrepreneurs‎.‎ Firms maximize profits intertemporarily‎,‎ i‎.‎ e‎.‎ their in‎- vestment leads to instantaneous sunk costs and offers flows of future profits‎.‎ Firms finance this investment by launching shares‎.‎ The capital market is per‎- fectly competitive‎,‎ implying that the return on a share is equal to the return on a bond‎.‎ As opposed to the capital market‎,‎ the goods market is imperfectly competitive‎.‎ As a result of investment‎,‎ firms enjoy market power‎.‎ That is‎,‎ firms may acquire the capability to provide a product that is differentiated in‎,‎ e‎.‎ g‎.‎ ‎,‎ styling‎,‎ technology‎,‎ accessibility‎,‎ or reputation‎.‎ The launch of a dif‎- ferentiated product allows to capture a market niche‎,‎ and successful firms may price above marginal cost‎.‎ The resulting profit flows are channelled to the firms‎'‎ shareholders‎.‎The introduction of monopolistic competition into growth theory is valuable‎:‎ real world economies may be portrayed rather by such an imperfect competition framework than by a perfect competition approach‎.‎ Starting with Romer ‎(‎1990‎)‎‎,‎ in growth theory‎,‎ modeling of imperfect competition has been notoriously bound to a focus on the impact of research and development ‎(‎R&D‎)‎ on economic growth‎.‎ In the existing literature‎,‎ growth‎-affecting investment is restricted to R&D investment‎.‎