Production complementarities and flexibility in a model of entrepreneurship

The focus of this paper is the flexibility in working hours as a motive for entrepreneurship. The model exhibits inflexibilities for workers and entrepreneurs, which arise due to complementarities in production. In addition, it allows for volatile value of leisure to make flexibility in hours desirable. Differences in occupation-specific flexibility, disciplined with the observed patterns in hours (level, persistence, dispersion) and income (persistence, dispersion), can explain relatively low income levels of entrepreneurs in the US and the occupation-specific distributions of working hours and income. Policy relevance of the model features is discussed using experiments of workweek restrictions and income taxation. (C) 2017 Elsevier B.V. All rights reserved.I gratefully acknowledge the support from the Ministerio Economia y Competitividad (Spain), Maria de Maeztu grant (MDM 2014-0431), and from Comunidad de Madrid, MadEco-CM (S2015/HUM-3444)

Who quits next? Firm growth in growing economies

We document novel facts about the relationship between aggregate growth and firm dynamics using a large set of countries. We argue that firm employment patterns are not necessarily informative about cross-country differences in aggregate growth because they are induced by changes in the productivity of a firm relative to others. In contrast, aggregate growth is linked to average firm-level productivity growth and firm age. We formalize this intuition through a tractable model of endogenous aggregate growth and firm dynamics where firms realize positive returns to investment with some probability. We find that cross-country disparities in this probability can account for two-thirds of the variation in aggregate growth.Yurdagul gratefully acknowledges the support from the Ministerio de Economía y Competitividad (Spain) (ECO2015-68615-P), María de Maeztu grant (MDM 2014-0431), and from Comunidad de Madrid, MadEco-CM (S2015/HUM-3444)

Value implications of open source software : an empirical outlook to the open innovation model

This thesis consists of three essays on open source software (OSS) phenomenon, which constitutes a suitable setting for investigating the open innovation paradigm and the benefits of firm-community collaborations for a firm. The first essay examines the impact of firms’ stocks of intellectual property right endowments on the relationship between firms’ OSS product portfolio and its firm value. The results suggest that firms taking more commercial actions in OSS paradigm enhance their firm value in the presence of large stocks of software patents. On the other hand, software trademark stocks have a negative effect on this relationship. Several potential explanations are proposed in the study, which emphasizes the importance of intellectual property right protection mechanisms for those firms that aim at building an OSS-based product portfolio. The second essay investigates the benefits that might accrue to a firm from their code contributions as reflected in stock market prices. The study builds on recent work in the area of community-based innovation and tries to explain why a firm might benefit from contributing to the commons. The hypotheses are tested on a novel data set that captures the stock market responses to 149 press releases made over a thirteen-year period. The findings suggest that open source code contributions generate positive, abnormal returns for the contributing firm. In addition, we find that contributions of new code rather than existing code generate greater value for the firm—and that contributions of new code to software projects targeted at end-users rather than developers systematically generate even greater returns. The third essay focuses on collaborations among firms and communities for obtaining better outcomes from open source projects. In specific, this study aims to disentangle how organizational design may affect the performance of an OSS project. Project’s management model and employee involvement in the project are treated as potential mediators that may have an effect on the aforementioned relationship. The empirical analysis is undertaken on a sample of OSS projects hosted on the platform SourceForge.net from December 2006 to December 2008. The findings of this study are three fold. First, being directly involved in a project with a specific policy on OSS has a positive effect on project’s performance. Second, coordination by firm has a negative effect on performance. Third, admin as an employee on main duty does not have a direct positive effect on performance. However, it positively moderates the aforementioned relationship. The contributions of these essays to the existing literature can be articulated as follows: The first essay contributes to the current debate on commercialization of OSS, mainly, by establishing the intermediary effect of firms’ IPR holdings on the relationship between OSS commercialization and performance. IPR mechanisms in the form of software patents and software trademarks needed to be investigated as they are crucial firm resources in appropriating returns. This study sheds light on how much these mechanisms matter for performance consequences of commercializing OSS. Moreover, the study empirically shows how mismatching strategies may harm a firm’s performance while the firm attempts to move towards a new business model for better outcomes. The second essay contributes to the literature on community-based innovation by enhancing our understanding of the process by which firms can work within communities. Literature on open innovation encapsulates community-based innovation, as well as other mechanisms by which the firm searches its external environment for knowledge. Other mechanisms—alliances, joint ventures, university collaborations— have been the object of much empirical and theoretical attention in the strategy and technology management literatures. In contrast, community-based innovation has been the object of less scholarly work, but has attracted the attention of academics and practitioners alike, and firm engagement with communities appears to be on the rise. It also contributes to the literature on learning, where communities can provide valuable knowledge to firms, by providing systematic empirical documentation. The third essay contributes to knowledge on benefits of collaborations between firms and OSS communities. Firm’s role in the complex coordination mechanism of the project on project’s success has been investigated. Along this line, the paper can also directly inform managers on the strategies they should apply to assure long term sustainability of their external knowledge sourcing activities through communities. Managing the boundaries of collaborations is essential. Written rules and guidelines lead to fruitful joint development of software.Esta tesis está compuesta por tres ensayos sobre el fenómeno de software de código abierto (SCA), lo que constituye un marco adecuado para la investigación del paradigma de la innovación abierta y los beneficios de las colaboraciones entre empresas y comunidades para una empresa. El primer ensayo analiza el efecto de las reservas de derechos de propiedades intelectuales de una empresa sobre la relación entre el portafolio de productos SCA de empresas y el valor de la empresa. Los resultados sugieren que las empresas que han adoptado medidas comerciales en el paradigma de SCA aumentan su valor en la presencia de grandes cantidades de patentes de software. Por otra parte, la existencia de marcas de software tiene un efecto negativo en esta relación. Varias explicaciones se proponen en el estudio, que hace hincapié en la importancia de los mecanismos de protección de derechos de propiedad intelectual para las empresas que tienen como objetivo la construcción de una cartera de productos basado en SCA. El segundo ensayo investiga los beneficios que una empresa podría obtener por sus contribuciones de código fuente como se refleja en los precios del mercado de valores. El estudio se centra en la línea de investigación de la innovación basada en la comunidad y trata de explicar cómo una empresa puede beneficiarse por contribuir al bien común. Las hipótesis se prueban con un dato nuevo que captura las reacciones del mercado de valores a 149 notas de prensa realizadas durante un período de trece años. Los resultados sugieren que las contribuciones de código abierto generan retornos anormales positivos para la empresa contribuyente. Además, descubrimos que las contribuciones de código nuevo respecto de aquellas de código existente generan mayor valor para la empresa. Y que las contribuciones de código nuevo a los proyectos de software dirigidos a los usuarios finales respecto de aquellos dirigidos a los desarrolladores, generan sistemáticamente aún mayores retornos. El tercer ensayo se centra en la colaboración entre empresas y comunidades para la obtención de mejores resultados de los proyectos de código abierto. En concreto, este estudio tiene como objetivo desentrañar cómo el diseño organizacional puede afectar al rendimiento de un proyecto de software libre. El modelo de gestión del proyecto y la participación de los empleados en el mismo son tratados como mediadores potenciales que pueden tener un efecto en la relación mencionada. El análisis empírico se realiza sobre una muestra de proyectos de software libre alojados en la plataforma SourceForge.net de diciembre 2006 a diciembre de 2008. Los hallazgos de este estudio son los siguientes. En primer lugar, participar directamente en un proyecto con una política específica en SCA tiene un efecto positivo en el rendimiento del proyecto. En segundo lugar, la empresa como la autoridad principal de coordinación tiene un efecto negativo en el rendimiento del proyecto. En tercer lugar, si el administrador es el empleado de la empresa no tiene un efecto directo sobre el rendimiento del proyecto. Sin embargo, modera positivamente la relación entre la empresa coordinadora y el rendimiento del proyecto. Las contribuciones de estos ensayos a la literatura existente pueden articularse de la siguiente manera: El primer ensayo contribuye al debate actual sobre la comercialización de la SCA, sobre todo, estableciendo el efecto intermediario de derechos de propiedad intelectual sobre la relación entre la comercialización de software libre y el rendimiento. Los mecanismos de derechos de propiedad intelectual en forma de patentes de software y las marcas de software necesitan ser investigados, ya que son recursos cruciales de una empresa para poder capturar retornos. Este estudio arroja luz sobre cuánto estos mecanismos importan para el desempeño de comercialización de SCA. Por otra parte, el estudio muestra empíricamente cómo las estrategias incompatibles pueden dañar el rendimiento de la empresa, mientras la empresa pretende avanzar hacia un nuevo modelo de negocio para mejorar su rendimiento. El segundo ensayo contribuye a la literatura de la innovación basada en la comunidad mediante la mejora de nuestra comprensión sobre el proceso por el que las empresas pueden trabajar con comunidades. La literatura sobre la innovación abierta encapsula la innovación basada en la comunidad, tanto como otros mecanismos por los que la empresa busca conocimiento en su entorno externo. Otros mecanismos- alianzas, empresa conjunta, colaboración con universidades- han sido objeto de atención empírica y teórica en la literatura de estrategia y de la gestión tecnológica. Por el contrario, la innovación basada en la comunidad ha sido objeto de trabajo escolar menos a menudo, pero ha atraído la atención de académicos y profesionales también, y la colaboración de las empresas con las comunidades parece estar en aumento. También contribuimos a la literatura del aprendizaje, donde las comunidades pueden proporcionar valiosos conocimientos a las empresas, aportando documentación empírica sistemática. El tercer ensayo contribuye al conocimiento sobre los beneficios de la colaboración entre las empresas y las comunidades de software libre. El papel de la empresa en el mecanismo complejo de la coordinación sobre el éxito del proyecto ha sido investigado. En esta línea, este trabajo también puede informar directamente a los administradores sobre las estrategias, que se deben aplicar, para asegurar la sostenibilidad de la adquisición de conocimiento desde los recursos externos a largo plazo, a través de las actividades de las comunidades. La gestión de los límites de la colaboración es esencial. Las normas y directrices escritas conducen al proceso beneficioso de creación conjunto de software

Trend shocks and sudden stops

Sudden Stops are characterized by large output drops, current account reversals and real exchange rate depreci-ation followed by a slow recovery, a pattern that has proven to be hard to capture with standard open economymodels. This paper extends the standard models with endogenous collateral constraints to include permanentincome (trend) shocks and studies the optimal policy design in this setting. Wefind that shocks to the trendplay an important role in generating a Sudden Stop followed by a slow recovery, a result that is also supportedby the data. With trend and transitory shocks, optimal capital control policy is procyclical, although less sothan under transitory shocks only.We gratefully acknowledge financial support from MDM 2014-0431, and Comunidad de Madrid, MadEco-CM (S2015/HUM-3444). Seoane gratefully acknowledges financial support from, Ministerio de Ciencia, Innovacion y Universidades (Spain) grant IJCI-2015-24465, "Programa propio de investigación" (PPI-2016-A-54) from Universidad Carlos III de Madrid, and the Ministerio Economía y Competitividad (Spain), grant ECO2016-76818-C3-1-P and ECO2014-56676-C2-1-P. Yurdagul gratefully acknowledges financial support from Ministerio Economía y Competitividad (Spain), grant ECO2015-68615-P., and from the Ministerio de Ciencia, Innovacion y Universidades (FJCI-2016-28864)

Endogenous hours and the wealth of entrepreneurs

US entrepreneurs typically work long hours in their firms and these hours form a large part of the firms' labor input. This paper studies the role of endogenous owner hours in shaping the wealth distribution among entrepreneurs. We introduce owners' endogenous labor supply into a model of entrepreneurial choice and financial frictions. The model fits well the levels and the dispersion of wealth among entrepreneurs. Long owner hours incentivize poor, highly productive individuals to be owners and help the most productive owners to accumulate large quantities of wealth. On net, owners working long hours decreases the median owner wealth and increase wealth dispersion among owners. Differently, the ability to work sufficiently short hours incentivizes owners to run low productivity firms with high wealth to income ratios. Finally, alternative calibrations ignoring the endogenous labor supply of owners lead to owners that are much richer than in the data and overstate the effect of financial frictions in the economy.We thank the Kauffman Foundation and the NORC Data Enclave for providing research support and access to the data used in this research. We also gratefully acknowledge the support from the Ministerio de Econom`ıa y Competitividad (Spain) (grant numbers ECO2014-56384-P and ECO2015-68615-P), Mar`ıa de Maeztu grant (MDM 2014-0431), and from Comunidad de Madrid, MadEco-CM (S2015/HUM-3444)

Hyperglycemia and Endothelial Dysfunction in Atherosclerosis: Lessons from Type 1 Diabetes

A clear relationship between diabetes and cardiovascular disease has been established for decades. Despite this, the mechanisms by which diabetes contributes to plaque formation remain in question. Some of this confusion derives from studies in type 2 diabetics where multiple components of metabolic syndrome show proatherosclerotic effects independent of underlying diabetes. However, the hyperglycemia that defines the diabetic condition independently affects atherogenesis in cell culture systems, animal models, and human patients. Endothelial cell biology plays a central role in atherosclerotic plaque formation regulating vessel permeability, inflammation, and thrombosis. The current paper highlights the mechanisms by which hyperglycemia affects endothelial cell biology to promote plaque formation

Sovereign Debt Restructurings

Sovereign debt crises involve debt restructurings characterized by a mix of face value haircuts and maturity extensions. The prevalence of maturity extensions has been hard to reconcile with economic theory. We develop a model of endogenous debt restructuring that captures key facts of sovereign debt and restructuring episodes. While debt dilution pushes for negative maturity extensions, three factors are important in overcoming the effects of dilution and generating maturity extensions upon restructurings: income recovery after default, credit exclusion after restructuring, and regulatory costs of book value haircuts. We employ dynamic discrete choice methods that allow for smoother decision rules, rendering the problem tractable.Yurdagul gratefully acknowledges the support from the Ministerio de Economía y Competitividad (Spain) (ECO2015-68615-P), María de Maeztu grant (MDM 2014-0431), and from Comunidad de Madrid, MadEco-CM(S2015/HUM-3444)

News, sovereign debt maturity, and default risk

Leading into a debt crisis, interest rate spreads on sovereign debt rise before the economy experiences a decline in productivity, suggesting that news about future economic developments may play an important role in these episodes. An empirical VAR estimation shows that a news shock has a larger contemporaneous impact on sovereign credit spreads than a comparable shock to labor productivity. A quantitative model of news and sovereign debt default with endogenous maturity choice generates impulse responses and a variance decomposition similar to the empirical VAR estimates. The dynamics of the economy after a bad news shock share some features of a productivity shock and some features of sudden stop events. However, unlike during sudden stop episodes, long-term debt does not shield the country from bad news shocks, and it may even exacerbate default risk. Finally, an increase in the precision of news allows the government to improve its debt maturity management, especially during periods of high stress in credit markets, and thus face lower yield spreads while increasing the amount of debt.Yurdagul gratefully acknowledges the support from the Ministerio de Economía y Competitividad (Spain) (ECO2015-68615-P), María de Maeztu grant (MDM 2014-0431), and from Comunidad de Madrid, MadEco-CM (S2015/HUM-3444)

Congenital cerebellar hypoplasia associated with BVD-MD virus infection in a naturally infected calf

The objectives of the present study were to describe pathomorphological and immunohistochemical features of congenital cerebellar hypoplasia associated with natural BVD-MD virus infection in a Holstein-Friesian calf. The characteristic macroscopical lesion was cerebellar hypoplasia, almost completely absent, with hydrocephaly. Cerebellar changes were cortical destruction, destructive changes of granule and Purkinje cells and irregular cavity formation of the folia. The positive antibody reaction against the BVD-MD virus was observed in the CNS, but not in the eyes and peripheral nerves