Knowledge spillover is an exchange of ideas among individuals.  In knowledge management economics , knowledge spillovers are a non-rival knowledge market costs incurred by a party not agreeing to assume the costs that a spillover effect of stimulating technological improvements in a neighbor through own innovation.   Such innovations often come from specialization within an industry. 
A recent, general example of a knowledge spillover Could Be the collective growth associated with the research and development of online social networking tools like Facebook , YouTube , and Twitter . Such tools have not only created a positive feedback loop , and a host of originally unintended benefits for their users, but have also created an explosion of new software, programming platforms, and conceptual breakthroughs that have perpetuated the development of the industry as a whole. The advent of online marketplaces, the use of profiles, the widespread democratization of information, And the interconnectivity between tools. (Eg CNN ‘s iReport ). These applications have been developed in the context of the .
There are two kinds of knowledge spillovers: internal and external. Internal knowledge spillover OCCURS if there is a positive impact of Knowledge entre Individuals Within an organism That Produces goods and / or services. An external knowledge spillover OCCURS When the positive impact of knowledge is entre Individuals without gold outside of a producing organism.  Marshall-Arrow-Romer (MAR) spillovers, Porter spillovers and Jacobs spillovers are three types of spillovers. 
March spillover Has Its Origins in 1890 Where the English economist Alfred Marshall Developed a theory of knowledge spillovers.  Kenneth Arrow (1962) and Paul Romer (1986) Knowledge spillovers were extended by economists . In 1992, Edward Glaeser , Hedi Kallal , José Scheinkman , and Andrei Shleifer pulled together the M arshall- A rrow- R omer views on knowledge spillovers and accordingly named the view MAR spillover in 1992. 
Under the Marshall-Arrow-Romer (MAR) spillover view, the proximity of firms Within a common industry Often affects how well knowledge travels Among firms to Facilitate innovation and growth.  The spillover of the spillover.  The exchange of ideas is broad from the employee to the employee.  The opportunity to exchange ideas that lead to innovations key to new products and improved production methods. 
Business parks are a good example of concentrated businesses that may benefit from MAR spillover.  Many semiconductor firms in Silicon Valley to take advantage of MAR spillover.  In addition, the film industry in Los Angeles, California and elsewhere relies on a geographic concentration of specialists ( directors , producers , scriptwriters , and set designers ) to bring together narrow aspects of movie-making into a final product.
However, research on the Cambridge IT Cluster (UK) suggests that technological knowledge spillovers could only happen rarely and are less important than other cluster benefits such as labor market pooling. 
Porter (1990), like MAR, argues that knowledge spillovers in specialized, geographically concentrated industries. He insists, however, that local competition, as opposed to local monopoly, fosters the pursuit and rapid adoption of innovation. He gives examples of Italian ceramics and gold jewelry industries, in which hundreds of firms are located together and fiercely compete to innovate since the alternative to innovation is demise. Porter’s externalities are maximized in cities with geographically specialized, competitive industries. 
Under the Jacobs spillover view, the proximity of firms from different industries affects the innovation and growth.  This is in contrast to MAR spillovers, which focus on firms in a common industry.  The diverse proximity of a Jacobs spillover brings together ideas from individuals with different perspectives to encourage an exchange of ideas and foster innovation in an industrially diverse environment. 
Developed in 1969 by urbanist Jane Jacobs and John Jackson  the concept That Detroit ‘s shipbuilding industry from the 1830s Was the critical antecedent leading to the 1890s development of the auto industry in Detroit since the gasoline engine firms Easily transitioned from building gasoline engines For ships to build them for automobiles. 
As information is Largely non-rival in nature some must Measures [ citation needed ] be taken to Ensure That, for the originator, the information remains in private asset . As the market can not do this efficiently, public regulationshave been implemented to facilitate a more appropriate equilibrium .
As a result, the concept of intellectual property rights have developed and ensured the ability of entrepreneurs to temporarily hold on to the profitability of their ideas through patents , copyrights , and other governmental safeguards. Conversely, such barriers to entry prevent the exploitation of informational developments by rival companies within an industry. [ Citation needed ]
On the other hand, When the research and development of a private firm results in a social benefit, unaccounted for dans le market price, Often Greater than the private return of the firm’s research, Then a subsidy to offset the underproduction of That benefit might be The benefit to the firm. Government subsidies are often controversial and may well lead to undesirable political repercussions, such as a taxpayers’ subsidy.  The concept of knowledge spillover is also used to justify subsidies to foreign direct investment , As foreign investors. 
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