Trade Reforms in a Global Competition Model: the Case of Chile

We use a global competition model of international trade to characterize the effects of trade reforms occurred in Chile at the end of the 70s. We calibrate the model and evaluate its results using a comprehensive plant-level dataset for the period 1979-96. The model is able to explain many of the effects of liberalization reforms on industry performance. We proceed by exploring the impact of preferential trade agreements negotiated by Chile in recent years with the European Union and the North American Free Trade Agreement.

Hysteresis in Export Markets

This paper develops a dynamic monopolistic competition model with heterogenous firms to analyze the effects of uncertainty on international trade. We characterize a stationary equilibrium, with N symmetric countries, where firms’ productivities evolve stochastically over time. Our model retains the main results of previous recent papers like Melitz (2003) and Bernard, Eaton, Jensen and Kortum (2003) and provides additional new predictions. Reentry export costs generate hysteresis in export participation creating a band of inaction within the stationary distribution of firms’ productivities. The decision to export becomes history-dependent and new entrants and incumbent firms might sustain temporary negative profits before becoming profitable. Most importantly, the model is very amenable to estimation and simulation, therefore representing a useful tool for analyzing the effects of trade policies. Several moments, like average age, size and productivity of different categories of firms (exporters, entrants, exiters,incumbents), the hazard rate of exiting or of becoming an exporter as a function of age and others have closed-form solutions that are crucial for matching static and dynamic features of the data.Hysteresis, Heterogeneous Firms, Firm Dynamics, Zipf's Law

A Theory of Entry and Exit into Exports Markets

This paper introduces persistent productivity shocks in a continuous-time mononopolistic competition model of trade with hetererogenous firms similar to Melitz (2003). In our model, the presence of sunk costs and uncertainty have three main consequences: first, firms export decisions become history-dependent. Second, the model generates firm dynamics and allows for substantial heterogeneity in export growth conditional on survival. Policy experiments modify the equilibrium along both the cross-sectional and time dimensions. Third, both the generated equilibrium firm size distribution and sales distribution of exporters into a foreign market are Pareto in the upper tail. All three consequences have been supported by empirical evidence. To solve the model we derive the stationary productivity distributions for exporters and non-exporters in general equilibrium. We point to the presence of a link between intra-industry firm heterogeneity and the degree of persistence in export status. Finally, we perform a numerical exercise to show how per-period fixed cost and up-front entry costs are differently related to persistence in export status for exporters and non-exporters.

The Cross Sectional Dynamics of Heterogenous Trade Models

In this paper we propose a framework for studying export dynamics and market specific flows in a multicountry model of trade with heterogenous firms. Countries are asymmetric in terms of their size, the size distribution of potential entrants, properties of firms idiosyncratic shocks, and trade barriers. The model has predictions in terms of cross-sectional moments and exporters dynamics. We show that persistent productivity shocks are enough to account for, qualitatively, many features of the data. In particular, the model is consistent with observed patterns of entry and exit across markets, export sales distribution, and the life cycle of new exporters.

ESTIMATING POTENTIAL GAINS TO COOPERATION FOR LIMITED WATER RESOURCES ALONG THE RIO GRANDE

We examine the potential gains from cooperation in the withdrawal of water from the Hueco Bolson aquifer that provides a substantial portion of municipal water supplies in El Paso, Texas and Ciudad Juarez, Mexico. The aquifer lies beneath the international border, and both cities operate independently regarding pumping rates and annual withdrawals. The natural the rate of recharge has been less than the sum of annual withdrawals since the early 1900s, and the resource likely will be depleted if current pumping rates are maintained. Optimal pumping rates and depths are described using a model that maximizes the sum of net benefits obtained from municipal water supplies in both cities. Those results are compared with pumping rates and depths obtained using a dynamic game-theory model of strategic behavior involving the two cities.Resource /Energy Economics and Policy,

The Margins of Multinational Production and the Role of Intrafirm Trade

In this paper we provide a quantitative analytical framework for analyzing trade and multinational production (MP), consistent with a set of stylized facts for trade and MP, among them that both exports and MP adhere to a gravity model. We propose a heterogeneous firm trade model where firms choose endogenously whether to serve foreign markets through MP or exports, where headquarters and affiliates are vertically integrated, and where firms face stochastic entry and demand shocks in each market. Using a unique firm-level data set on production, trade and MP, we establish key regularities about the entry and sales patterns of multinationals that support the model building blocks. We develop a new maximum likelihood estimator that connects the theory directly to the data and that allows us to identify key parameters of the model, explore its plausibility and implications. Our main result is that intra-firm trade plays a crucial role in shaping the geography of MP. This conclusion is robust to any geographical distribution of fixed costs

Manipulación y Educación

En torno al proceso educativo gravitan un conjunto de realidades que se relacionan positiva o negativamente con él. Las primeras, como formación, perfeccionamiento, desarrollo, tienden a confundirse con la educación. Las segundas, en cambio, son repelidas por la realidad educativa y se diferencian o separan de ella. Entre estas últimas, se encuentran el condicionamiento, el adoctrinamiento, la manipulación

Advancing student-staff partnership through the unique position of GTAs

In this paper we argue that Graduate Teaching Assistants (GTAs) are in a liminal position between taught students and fully fledged academic staff. This unique position provides the context for their knowledge about learning and teaching, which is situated in the particularity of their perspective. This singular perspective can be broadened through the kind of scholarly activity involved in student-staff partnership to better reflect the multiplicity of student experiences. GTAs’ unique position allows them to better bridge the perspectives of staff and students, such that they can play an important role mediating between the two and providing invaluable insight to teaching and learning enhancement. Furthermore, GTAs have much to gain from working in partnership, in particular gaining a sense of being valued in a role that often feels dismissed. Nevertheless, there are particular dangers of the relationship falling into a familiar apprenticeship pattern and not fulfilling GTAs’ expectations if staff fail to buy-into the ethos of partnership

Desarrollo de "Sunscald" en manzana CV. Granny Smith en almacenaje refrigerado

Resumen (Spanish, English)52 p.Durante el almacenaje de manzanas, es posible que aparezcan ciertas anomalías originadas por factores de pre y post-cosecha. Los más comunes son el escaldado superficial, bitter pit y lenticelosis. Existe un desorden similar al escaldado superficial, denominado “Sunscald”, cuya principal característica es un pardeamiento de la piel inducido por una fuerte exposición de la fruta al sol. Cuando el daño no es visible a cosecha, la fruta desarrolla, en almacenaje, un pardeamiento en la zona de exposición, siendo ineficientes las aplicaciones de antioxidantes. Su control es de carácter preventivo, similar a los utilizados en el control de golpe de sol. Durante la temporada 1996/1997 en la localidad de Cordillerilla, 25 km al oeste de Curicó (35ºS, 71ºO), se realizaron tres ensayos cuya finalidad fue determinar la susceptibilidad a desarrollar “sunscald” en almacenaje de manzanas cv. Granny Smith. El primero de ellos muestra la susceptibilidad del desorden en términos de la posición de los frutos dentro del dosel. El segundo, el efecto de la aplicación de Difenilamina (DPA) y tiempo de almacenaje sobre la incidencia del desorden en distinta coloración inicial de la fruta a cosecha; y el tercer ensayo, la correlación de mediciones objetivas de color con el contenido de clorofila de los frutos. Se recolectaron frutos de la zona más expuesta al sol (lado poniente), en dos épocas, correspondientes a la primera y última comercial del huerto, manteniendo la fruta por un periodo de almacenaje refrigerado de 4 meses (m) y 4 m +7 días a 20°C. Se evaluó incidencia y severidad del desorden color, contenido de clorofila; capacidad antioxidante y madurez de la fruta. Así mismo, para cada evaluación, la mitad de la fruta fue tratada con DPA (2000 ppm), para diferenciar “sunscald” del escaldado superficial. Los resultados obtenidos mostraron una baja incidencia y severidad de “sunscald” independiente de la posición de la fruta dentro del dosel por lo que se puede pensar que no se alcanzó el umbral de daño, en fruta de apariencia sana a cosecha. No hubo efecto de la aplicación de DPA en el control del desorden, la coloración verde no mostró incidencia, en cambio las coloraciones rosadas y amarillas, mostraron un nivel superior al 30%. No fue posible establecer una correlación entre el contenido de clorofila o capacidad antioxidante con mediciones objetivas de color , dado que mostraron bajos niveles de coeficiente de correlación