We examine whether an incumbent active in a market with strong network effects can be challenged by an entrant already active in the market of a complementary good. When only the entrant benefits ...from such a complementarity in the network market, we find that it can conquer such a market if and only if the degree of complementarity is large enough. In such cases, the entrant may use the network good as a loss-leader so as to expand the market of the complementary good. When the incumbent's network good is enhanced too by the existence of the complementary good, we study if the entrant is better or worse off. Finally, we argue that, even though pure bundling may be an effective entry strategy and it may be socially desirable, it may be harmful for the entrant to use it.
We present a dynamic model where the accumulation of patents generates an increasing number of claims on sequential innovation. We study the equilibrium innovation activity under three regimes: ...patents, no-patents and patent pools. Patent pools increase the probability of innovation with respect to patents, but we also find that: (1) their outcome can be replicated by a licensing scheme in which innovators sell complete patent rights, and (2) they are dynamically unstable. We find that none of the above regimes can reach the first or second best. Finally, we consider patents of finite duration and determine the optimal patent length.
When innovation is sequential, the development of new products depends on the access to previous discoveries. As a consequence the patent system affects both the revenues and the cost of the ...innovator. We construct a model of sequential innovation in which an innovator uses n patented inputs in R&D to invent a new product. We ask three questions: (i) what is the net effect of patents on innovation as technologies become more complex (n increases)? (ii) are patent pools welfare enhancing? (iii) what is the optimal response of patent policy as technological complexity increases? We find that the answers to these questions depend on the degree of complementarity and substitutability between the inputs used in research.
Mixed Source Casadesus-Masanell, Ramon; Llanes, Gaston
IDEAS Working Paper Series from RePEc,
01/2009
Paper
Odprti dostop
We study competitive interaction between profit-maximizing firms that sell software and complementary goods or services. In addition to tactical price competition, we allow firms to compete through ...business model reconfigurations. We consider three business models: the proprietary model (where all software modules offered by the firm are proprietary), the open source model (where all modules are open source), and the mixed source model (where a few modules are open). When a firm opens one of its modules, users can access and improve the source code. At the same time, however, opening a module sets up an open source (free) competitor. This hampers the firm's ability to capture value. We analyze three competitive situations: monopoly, commercial firm vs. non-profit open source project, and duopoly. We show that: (i) firms may become "more closed" in response to competition from an outside open source project; (ii) firms are more likely to open substitute, rather than complementary, modules to existing open source projects; (iii) when the products of two competing firms are similar in quality, firms differentiate through choosing different business models; and (iv) low-quality firms are generally more prone to opening some of their technologies than firms with high-quality products.
Background: Radical prostatectomy by lateral approach allows performing a prostatectomy through a buttonhole, with direct access to the seminal vesicle and fully sparing the anterior pubovesical ...complex. Our aim is to show the results of reproducing the technique of robotic radical prostatectomy by lateral approach, in terms of intraoperative, postoperative, oncological and functional parameters. Methods: We analyzed 513 patients submitted to robotic radical prostatectomy by lateral approach from January 2015 to March 2021, operated on by two surgeons in our institution. The oncological and functional results of both surgeons were compared. Results: When comparing both surgeons, the rate of positive surgical margins (PSM) was 32.87% and 37.9% and significant surgical margins (PSM > 2 mm) were 5.88% and 7.58% (p = 0.672) for surgeon 1 and surgeon 2, respectively. Immediate continence was 86% and 85% and sexual potency at one year 73% and 72%, with a similar rate of complications for surgeon 1 and 2. Conclusions: Radical prostatectomy by the lateral approach technique with preservation of the anterior pubovesical complex is reproducible and offers good oncological and functional results.
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