Engineering a venture capital market: lessons from the American experience

The venture capital market and firms whose creation and early stages were financed by venture capital are among the crown jewels of the American economy. Beyond representing an important engine of macroeconomic growth and job creation, these firms have been a major force in commercializing cutting edge science, whether through their impact on existing industries as with the radical changes in pharmaceuticals catalyzed by venture-backed firms commercialization of biotechnology, or by the their role in developing entirely new industries as with the emergence of the internet and world wide web. The venture capital market thus provides a unique link between finance and innovation, providing start-up and early stage firms - organizational forms particularly well suited to innovation - with capital market access that is tailored to the special task of financing these high risk, high return activities

The Political Ecology of Takeovers: Thoughts On Harmonizing the European Corporate Governance Environment

Economic policy debate in the United States during the 1980s focused on the dynamics of bidder and target tactics in hostile takeovers. Confronted with the largest transactions in business history, financial economists took advantage of developments in econometric techniques to conduct virtually real time studies of the impact on firm value of each new bidder tactic and target defense. For courts and lawyers, hostile takeovers subjected standard features of corporate law to the equivalent of a stress x-ray, revealing previously undetected doctrinal cracks. Congress held seemingly endless hearings on the subject, although managing to enact only relatively innocuous tax penalties on particular defensive tactics the public found especially offensive. State legislatures, closer to the political action, acted more substantively, if less wisely. Whether or not takeovers created new wealth they did result in its transfer, and at least one of the parties from whom wealth was transferred – target management – had remarkable influence in state legislatures. When labor also came actively to oppose hostile takeovers, the coalition was virtually unstoppable. The decade saw some thirty-four states pass more than sixty-five major laws restricting corporate takeovers, including states discouraging partial offers and front-end loaded offers. The 1980s have now closed transactionally as well as chronologically. The first quarter of 1991 marked the lowest level of merger and acquisition activity since the first quarter of 1980. The passing of this remarkable decade invites a broader perspective, which can be helpfully thought of as the political ecology of takeovers. An ecological perspective builds on the proposition that phenomena are embedded in interactive systems – a rich web of mutually dependent relationships. Thus, a seemingly independent event cannot be fully evaluated without understanding how it relates to the environmental forces to which it was a response and which, in turn, respond to it. What the narrow focus of the 1980s debate missed was an appreciation of the complex economic corporate governance and political environments in which hostile takeovers are embedded. Corporate acquisitions are a response to real conditions in the economic environment. The choice among acquisition techniques, most importantly between friendly and hostile transactions, depends both upon the economic motivation for the transaction and upon conditions in the corporate governance environment. Finally, conditions in the corporate governance environment are directly influenced by politics; both what is allowed and prohibited is defined, in the first instance, by legislation. My goal in this article is two-fold. I begin by sketching the political ecology of takeovers in the United States – the interaction of economics, corporate governance and politics that shaped the experience of the 1980s. I then make a tentative effort at applying the insights gained from an ecological perspective to the current endeavor to change dramatically the European corporate governance environment through the harmonization of takeover and company law in the European Community. Sheltered by the cloak of political naivete commonly allowed those attempting comparative analysis from a distance, I will argue that an ecological understanding of takeovers suggests a different approach than that reflected so far in the debate over the terms of harmonization. This approach is based on what I term the mutability principle

Cue combination for 3D location judgements

Cue combination rules have often been applied to the perception of surface shape but not to judgements of object location. Here, we used immersive virtual reality to explore the relationship between different cues to distance. Participants viewed a virtual scene and judged the change in distance of an object presented in two intervals, where the scene changed in size between intervals (by a factor of between 0.25 and 4). We measured thresholds for detecting a change in object distance when there were only 'physical' (stereo and motion parallax) or 'texture-based' cues (independent of the scale of the scene) and used these to predict biases in a distance matching task. Under a range of conditions, in which the viewing distance and position of the tarte relative to other objects was varied, the ration of 'physical' to 'texture-based' thresholds was a good predictor of biases in the distance matching task. The cue combination approach, which successfully accounts for our data, relies on quite different principles from those underlying geometric reconstruction

An automated calibration method for non-see-through head mounted displays

Accurate calibration of a head mounted display (HMD) is essential both for research on the visual system and for realistic interaction with virtual objects. Yet, existing calibration methods are time consuming and depend on human judgements, making them error prone, and are often limited to optical see-through HMDs. Building on our existing approach to HMD calibration Gilson et al. (2008), we show here how it is possible to calibrate a non-see-through HMD. A camera is placed inside a HMD displaying an image of a regular grid, which is captured by the camera. The HMD is then removed and the camera, which remains fixed in position, is used to capture images of a tracked calibration object in multiple positions. The centroids of the markers on the calibration object are recovered and their locations re-expressed in relation to the HMD grid. This allows established camera calibration techniques to be used to recover estimates of the HMD display's intrinsic parameters (width, height, focal length) and extrinsic parameters (optic centre and orientation of the principal ray). We calibrated a HMD in this manner and report the magnitude of the errors between real image features and reprojected features. Our calibration method produces low reprojection errors without the need for error-prone human judgements

Darboux dressing and undressing for the ultradiscrete KdV equation

We solve the direct scattering problem for the ultradiscrete Korteweg de Vries (udKdV) equation, over $\mathbb R$ for any potential with compact (finite) support, by explicitly constructing bound state and non-bound state eigenfunctions. We then show how to reconstruct the potential in the scattering problem at any time, using an ultradiscrete analogue of a Darboux transformation. This is achieved by obtaining data uniquely characterising the soliton content and the `background' from the initial potential by Darboux transformation.Comment: 41 pages, 5 figures // Full, unabridged version, including two appendice