Aghion, Van Reenen and Zingales (2013) find that institutional ownership causes an increase in innovation as measured by citation-weighted patent counts. To identify a causal effect, they use membership in the S&P 500 as an instrument for institutional ownership in a panel regression. We first...

This study investigates the relationship between patenting activity, productivity, and market competition at the firm level. We focus on the Information and Communication Technology (ICT) industry as a particular case of an innovative sector whose contribution to modern economies is pivotal. For...

I show that mature patent-practicing firms respond to windfall profits derived from exogenously extended patent protection time by engaging in external patent acquisitions that diversify their patent portfolios into new technologies. By exploiting the random timing of patent term expiry dates...

This paper discusses the impact of a firm's technology portfolio on its market value. Two concepts are used to characterize a firm's portfolio: the number of technological fields and the degree of relatedness within the portfolio characterized by the amount of joint occurrences of patents in...

This paper explores the sources of firm-level scale economies in R&D, based on unique project-level data from a new large-scale survey of Japanese inventors, matched with firmlevel data. We focus on four sources: complementary assets, internal and external knowledge inflows, and inventor team...

This paper discusses the impact of a firm's technology portfolio on its market value. Two concepts are used to characterize a firm's portfolio: the number of technological fields and the degree of relatedness within the portfolio characterized by the amount of joint occurrences of patents in...

The localization of knowledge flows has been attributed to agglomerations of knowledge-intensive firms in a region, but I argue that knowledge localization is not consistent with the wider social and professional networks of the firms' employees. I predict that small, knowledge-intensive firms...

We formulate a simple model of optimal defensive disclosure by a monopolist facinguncertain antitrust enforcement and test its implications using unique data on defensivedisclosures and patents by IBM during 1955-1989. Our results indicate that strongerantitrust enforcement leads to more...

We formulate a simple model of optimal defensive disclosure by a monopolist facinguncertain antitrust enforcement and test its implications using unique data on defensivedisclosures and patents by IBM during 1955-1989. Our results indicate that strongerantitrust enforcement leads to more...