Browsing by Author "Ignacio Guzman, Juan"

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    A method to estimate the robustness of the secondary refined copper supply function
    (2023) Rivera, Nilza; Ignacio Guzman, Juan; Lagos, Gustavo
    Knowing the factors that influence the secondary refined copper supply behavior has been fundamental in generating a copper market model and developing public and corporate policies. When analyzing the explanatory variables used in the existing models in the literature, it is possible to observe high variability in estimating the parameters when modifying the availability of information or changing the observation period. Based on this, we argue that only some explanatory variables will have robust estimated parameters, which means that they are unbiased, stable (i.e., they do not vary significantly when the specification of the equation or the number of observations changes), and with asymptotic convergence over time. This work defines and validates a method to select robust explanatory variables capable of quantifying the refined secondary supply of copper (or any other variable) in a given period. Using a database with 23 explanatory variables in the period 1960-2017, we characterize the estimated parameters with high and low robustness, thus supporting the proposed hypothesis. The results obtained allowed identifying those variables with low uncertainty in estimating their parameters, with a high statistical significance, and with a low standard deviation. This allows to obtain a robust function for the secondary refined copper supply in the long term, capturing essential elements of reality.
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    Evaluation of econometric models of secondary refined copper supply
    (2021) Rivera, Nilza; Ignacio Guzman, Juan; Joaquin Jara, Jose; Lagos, Gustavo
    Copper is essential in attaining a sustainable development path due to its prominent role in the electromobility and renewable energy industries. In 2019 refined copper usage was 23.5 million tons, of which primary copper supplied 86.3%, and the remaining 13.7% was provided by secondary metal. In the future, copper recycling would increase significantly concerning primary copper supply to meet the goal of decreasing greenhouse gases emissions. Secondary copper production reduces energy consumption by 85% and greenhouse gas emissions by 65% compared to average primary sources.
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    Evolution of the Surface Area of Critical Lagoon Systems in the Salar de Atacama
    (2022) Ignacio Guzman, Juan; Retamal, Candelaria; Faundez, Patricio; Joaquin Jara, Jose
    The Salar de Atacama in northern Chile hosts the biggest lithium reserves globally. However, concerns have arisen regarding the environmental impact of lithium extraction on its basin; in particular, the possible drought of its lagoons that sustain unique natural ecosystems. This investigation implemented an image processing and statistical methodology to assess the area evolution and dynamic behavior of these main water bodies between 1986 and 2018. Results showed that these lagoon systems have not presented significant changes despite increasing lithium production, even for the years of large brine extraction. The analysis indicated that the total surface area of the lagoons varied within a restricted range at 95% confidence level: on average, of the total area covered by these systems 0.03% could have been lost or 0.01% could have been gained per year. Moreover, a multivariate analysis indicated that brine extraction did not have a negative impact on the evolution of the surface areas of the lagoons during the last three decades.
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    OUTPUT-EXPANDING COLLUSION IN THE PRESENCE OF A COMPETITIVE FRINGE
    (WILEY-BLACKWELL PUBLISHING, INC, 2010) Montero, Juan Pablo; Ignacio Guzman, Juan
    Following the structure of many commodity markets, we consider a few large firms and a competitive fringe of many small suppliers choosing quantities in an infinite-horizon setting subject to demand shocks. We show that a collusive agreement among the large firms may not only bring an output contraction but also an output expansion (relative to the non-collusive output level). The latter occurs during booms and is due to the strategic substitutability of quantities. We also find that the time at which maximal collusion is most difficult to sustain can be either at booms or recessions. The international copper cartel of 1935-39 is used to illustrate some of our results.