Assortative Matching and the Education Gap

This paper attempts to explain the decrease and reversal of the education gap between males and females. Given a continuum of agents, the education decisions are modelled as an assignment game with endogenous types. In the first stage agents choose their education level and in the second they participate in the labor and marriage markets. Competition among potential matches ensures that the efficient education levels can always be sustained in equilibrium, but there may be inefficient equilibria. Combining asymmetries intrinsic to the modelled markets the model reproduces the observed education gap.Assortative matching, pre-marital investments, efficiency

The impossibility of strategy-proof clustering

Clustering methods group individuals or objects based on information about their similarity or proximity. When the raw information to generate clusters cannot be easily observed or verified, the cluster designer must rely on information reported by individuals behind the observations. When these individuals receive utility from a public decision taken with aggregated data within each own's cluster and have single-peaked preferences, we prove that there do not exist clustering methods such that truth-revealing behavior is always a dominant strategyclustering methods

Major League Baseball Draft Pick Compensation: How To Evaluate The Marginal Revenue Product Of Labor Of Drafted Players

The Major League Baseball draft is virtually the only means by which US and US territory born players have access to becoming major league baseball players. As a condition of their initial contracts, players are subjected to initial contract terms, that limit their traditional free market ability to earn a salary commensurate with their actual worth. This research attempts to quantify the difference between what players would earn on the open market, as free agents, and what they earn by being controlled by baseball’s reserve clause, by analyzing the current compensation system established by Major League Baseball, how drafted players have limited leverage in negotiations, and whether their compensation approximates actual provided value. The result of this analysis is clear that players on their initial contracts over perform relative to their compensation, relative to players who signed open-market contracts

The impact of export-oriented entrepreneurship on regional economic growth

Although export-oriented new ventures and the field of international entrepreneurship have received considerable attention by scholars during the last decade (Oviatt and McDougla, 2005), their potential economic impact has not been sufficiently analyzed yet. To the best of our knowledge, no studies on this issue have been carried out at regional level. Despite the increasing impact of globalization, regions have emerged as the essential and active unit of economic development process (Scott and Stopper, 2003). Regions are influential environments fostering entrepreneurship (Feldman, 2000). This is especially true for knowledge-based entrepreneurship since proximity to knowledge sources matters in order to discover opportunities and exploit them (Audretsch, 1998). Moreover, regions differ culturally and economically, and such differences encourage or discourage people to venture in entrepreneurial activity. We analyze the impact of export-oriented entrepreneurship on regional growth using data provided by the Global Entrepreneurship Monitor project and the Spanish Institute of Statistics, for 17 NUTS-2 Spanish regions over a period of six years. After controlling for catching-up effects (van Stel et al., 2005), as well as, other drivers of economic growth (e.g. change in technology capability and human capital), we found evidence that those regions with a higher percentage of adult population involved in export-oriented entrepreneurship experience a higher GDP growth. This relationship is greater as the level of foreign customers served by the entrepreneurial initiatives is substantially higher (i.e., at least 1%, 25% or 75% of customers located abroad). These results support those found at national level by Hessels and van Stel (2009). However, our paper adds to the extant literature on entrepreneurship by analyzing the role of entrepreneurial activity with different levels of export intensity on regional growth under a longitudinal context. Policy implications derived from these results suggest that trade policies for export promotion among new ventures should be carried out at regional level. Otherwise, exporting new ventures may concentrate only on certain regions, which would help to increase differences on growth within a nation.

Downward Adjustments in a Cyclical Environment: The Case of Chilean Pelagic Fisheries

This paper offers an empirical analysis of harvest functions for the two main Chilean pelagic fisheries, which are characterized by cyclical fish abundance. Two main results are obtained. First, we identify production-side effects that weaken the incentives to adjust towards lower fishing efforts: (i) increasing returns in the use of variable inputs are observed, which are strengthened by external economies associated to aggregate search effort for fish; and (ii) catch yields sensitive to changes in abundance, but where the strength of this effect decreases as abundance declines. Second, we confirm the empirical relevance of Translog harvest technologies. This contradicts a frequent practice in bio-economic models, i.e. considering harvest-input elasticities as being constant and independent from the scale of production.Chilean pelagic fisheries; harvest functions; panel estimation; fishing cycles.

Paisaje y gestión de los recursos vegetales en el yacimiento romano de Gabia (Granada) a través de la Arqueobotánica

Anthracological and carpological findings are presented for the Roman villa of Gabia, which gives us important knowledge concerning the exploitation of the environment and the diverse use of plant resources. The results confirm the existence of a strongly humanized landscape, with relatively open vegetation where shrubby and thicket species have great importance, with the Holm oak and the Aleppo pine being the representatives of the tree stratum. Crops would predominate the setting, where cereals, i.e. barley and glumeless wheat, occupying land reclaimed from the forest, while legumes such as chick-peas, lentils, grass peas, sweet peas, and fava beans were also cultivated. The fuel for fireplaces came from wood gathered from the forest as well as the remains from pruning cultivated trees. For the construction of posts and beams, large trees were used, these offering long, straight logs in the case of pines and elms, and branches of great strength such as walnut and Holm oak. For the construction of roofs, shrub species were used: common junipers, legumes, broom, and rosemary.<br><br>Se presentan los resultados obtenidos por la antracología y la carpología en la villa romana de Gabia, que nos dan un importante conocimiento sobre la explotación del medio y del uso de los recursos vegetales utilizados con diversas finalidades. Estos resultados confirman la existencia de un paisaje fuertemente antropizado, con una vegetación relativamente abierta donde tienen una gran importancia las especies arbustivas y de matorral, quedando sólo la encina y el pino carrasco como representantes del estrato arbóreo. Los cultivos predominarían en el entorno, siendo los cereales, con el trigo desnudo y la cebada vestida, los que ocuparían parte de las tierras ganadas al bosque, desarrollándose también leguminosas como garbanzos, lentejas, guijas, guisantes y habas. El combustible para los hogares provenía tanto de leña recogida en el bosque, como de los deshechos de las podas de los árboles cultivados. Para la construcción de postes y vigas se recurre a árboles de gran porte, que pueden ofrecer leños rectos y largos, caso de los pinos y el olmo y ramas de gran resistencia como son el nogal y la encina; mientras que para la construcción de los techos se utilizan especies arbustivas: enebros, leguminosas, retama y romero

Analysis of Energy Management and Financial Planning in the Implementation of PV Systems

This paper presents the analysis of energy management and financial planning that is carried out in the design and implementation of photovoltaic systems in urban areas of the city of Barranquilla, Colombia. A questionnaire with a Likert scale and 36 items was designed, which was answered by subjects with managerial functions of the 16 companies dedicated to the implementation of photovoltaic (PV) projects in Barranquilla. The instrument was validated by expert judgment with a reliability of 0.84 with Cronbach's Alpha. For the analysis of results, techniques of central tendency and variability were used. The results show that energy management in the implementation of PV projects is moderate, indicating that there is no predominant presence of indicators of improvement and energy performance in these projects. Financial planning has a moderate significance, indicating that the financial analysis methods that are being used in these PV systems projects have a basic analysis. Keywords: Energy Management, Financial Planning, Photovoltaic Energy JEL Classifications: P18, P11, Q20 DOI: https://doi.org/10.32479/ijeep.758

Conjunctival Autograft With Fibrin Glue for Pterygium: A Long Term Recurrence Assessment

Pterygium is an old challenge for ophthalmic surgeons. Its final resolution is surgical intervention. New surgical techniques have been introduced to improve the outcome, however, the possibility of recurrence always exists. The purpose of this study was to evaluate the pterygium recurrence rate with a long-term follow-up, after surgery was performed with conjunctival autograft and fibrin glue as a biological adhesive. A retrospective case-series study was performed, reviewing cases operated from May 2008 to May 2018 with at least 1 year of follow-up in a private clinic in Buenos Aires, Argentina. The evaluation time-points were at 1 day, 20 days, 6 months, 1 year after surgery and then every year. All the procedures were performed by the same surgeon in single center. Topical Mitomycin C (MMC), 5-Fluorouracil (5-FU), cauterization and/or amniotic membrane were not used in any case. From a total of 159 operated eyes (82/77 women/men), pterygium was recurred in 7 eyes (4.4%); all of them detected at the second follow-up time-point (at day 20). Intraoperative complications did not occur, but at the postoperative stage, one case presented a conjunctival granuloma, which was surgically resolved. In conclusion, a low pterygium recurrence rate was observed after conjunctival autograft with fibrin glue. In our study, recurrence was found at the postoperative first month and did not recur until the end of follow-up for 10 years. Epub: October 1, 2019

Ensayo preliminar: Almidón de “Malanga†Colocasia esculuenta, como ayudante de floculación en la potabilización del agua

Para lograr la clarificación del agua en los procesos de potabilización, se utilizan sustancias químicas u orgánicas que poseen la característica de formar partículas sedimentables que pueden ser removidas mediante procesos físico-mecánicos. El uso de coagulantes y ayudantes de floculación naturales viene aumentando; como consecuencia de la presencia del aluminio en el agua entregada a la población, este tipo de coagulantes químicos, causan o están directamente asociados a los problemas del sistema nervioso central; además de provocar envejecimiento prematuro. La investigación se basó en un primer ensayo para determinar las propiedades del almidón de Malanga como ayudante de floculación en la potabilización del agua, ya que en investigaciones realizadas anteriormente con almidón de cereales como el maíz, y raíces como la yuca, han dado resultados positivos. En los ensayos realizados con almidón de Malanga se pudo establecer la eficiencia a la hora de remover turbiedad, color y otros elementos no deseables