This paper studies the role of intrinsic motivation, reputation and reciprocity in driving open source software innovation. We exploit the observed pattern of contributions - the 'revealed preference' of developers - to infer the underlying incentives. Using detailed information on code...

We analyse the determinants of the decline in measured research productivity (the patent/R&D ratio) using panel data on manufacturing firms in the US for the period 1980-93. We focus on three factors: the level of demand, the quality of patents, and technological exhaustion. We first develop an...

This Paper shows how microeconomic data on investment plans can be used to study the structure of risk faced by firms. Revisions of investment plans form a martingale, and thus reveal the underlying shocks driving investment. We decompose revisions in investment plans into micro, sector and...

We investigate how liability rules and property rules affect the incentives to invest in research tools. We argue that it is hard to deter infringement under any of the enforcement regimes available. However, counterintuitively, a credible threat of infringement can actually be beneficial to the...

This paper shows that the process of enforcing patent rights both dilutes and distorts Research and Development (R&D) incentives. We examine the characteristics of litigated patents by combining, for the first time, information about patent case filings from the US district courts with detailed...

We study how the market for innovation affects enforcement of patent rights. Conventional wisdom associates the gains from trade with comparative advantage in manufacturing or marketing. We show that these gains imply that patent transactions should increase litigation risk. We identify a new...

Using new data on citations to university patents and scientific publications, and measures of distance based on Google maps, we study how geography affects university knowledge diffusion. We show that knowledge flows from patents are localized in two respects: they decline sharply with distance...

In a model with moral hazard and assymmetric information, we show that it can be welfare-improving to differentiate patent lives when firms have different R&D productivities. A uniform patent life provides excessive R&D incentive to low-productivity firms, and too little to high ones. The...

This paper develops a framework for evaluating the social returns to infrastructure investments that intensify product market competition. We use a circular model with asymmetric production costs both for incumbent firms and potential entrants, where unit transport cost measures the intensity of...

We study how fragmentation of patent rights ('patent thickets') and the formation of the Court of Appeal for the Federal Circuit (CAFC) affected the duration of patent disputes, and thus the speed of technology diffusion through licensing. We develop a model of patent litigation which predicts...