The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform
Lourdes Trujillo - One of the best experts on this subject based on the ideXlab platform.
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Economies of scale and scope for Cargo Handling firms in Spanish ports
2020Co-Authors: Lourdes Trujillo, Sergio R. Jara-díazAbstract:Cargo Handling in ports is a multioutput activity, as freight can arrive in many forms like containers, bulk, rolling stock, or non-containerised general Cargo. Each type of movement involves the use of both common and specialised inputs. In this paper the operation of Cargo Handling firms in ports is analysed by means of the estimation of a multioutput cost function, using monthly data on three firms located at the Las Palmas port in Spain. Both size and traffic mix is first shown to be sufficiently diverse as to allow for a reliable estimation of a representative flexible (quadratic) cost function that permitted the calculation of product specific marginal costs, economies of scale (general and by firm) and economies of scope. Containerised Cargo is shown to present the smallest marginal costs for all firms, while non-containerised general Cargo has the largest. The largest firm exhibits constant returns while the smaller are still in the increasing returns zone, which suggests the convenience of increasing their scale of production. All firms exhibit economies of scope for every possible partition of the product set, which indicates the inconvenience of Cargo Handling specialisation by type. Prevailing average minimum prices are found to be of comparable magnitude (slightly larger) regarding the estimated marginal costs. This observed minimum price level suggests that they could be potential second best (Ramsey) prices needed to cover costs in the presence of increasing returns. For the covering abstract see ITRD E126595.
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On the proper modelling of multioutput port Cargo Handling costs
Applied Economics, 2008Co-Authors: Sergio R. Jara-díaz, Beatriz Tovar, Lourdes TrujilloAbstract:Cargo Handling activities involve various heterogeneous outputs, e.g. general Cargo, containers, dry and liquid bulk and so on. These activities in ports, however, have been usually analysed using aggregate descriptions of output such as total tons moved. The main purpose of this article is to show that ignoring this heterogeneity may lead to two types of problems: (i) the underestimation of the relevance of key dimensions (i.e. marginal costs per product and economies of scope) and (ii) a bias in the estimates of the relevance of other dimensions (economies of scale). To do so, we rely on a unique new dataset on three Cargo Handling firms operating in a Spanish port between 1991 and 1999. We use it to estimate both a multi-output cost for these three operators, as well as an aggregate cost function. The policy conclusions are derived from an explicit and detailed comparison of these two sets of estimates.
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firm and time varying technical and allocative efficiency an application to port Cargo Handling firms
International Journal of Production Economics, 2007Co-Authors: Ana Rodriguezalvarez, Beatriz Tovar, Lourdes TrujilloAbstract:Abstract In this paper we present an econometric model to calculate both, the technical and the allocative efficiency in Cargo Handling firms in the port of Las Palmas (Spain). To achieve these aims, we estimate a system of equations consisting of a translog input distance function and cost shares equations. Using this procedure we can check the hypothesis in which, given technology and prices, terminal port inputs are not optimally allocated in the sense that costs are not minimized. The main contribution of this paper is to apply an empirical model that allows the unbiased estimation of allocative inefficiency of input use in two ways: an error components approach and a parametric approach. We also avoid the Greene Problem and allow allocative inefficiency to be systematic. Both size and traffic mix are first shown to be sufficiently diverse as to allow for a reliable estimation of a representative flexible (translog) function.
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multioutput analysis of Cargo Handling firms an application to a spanish port
Transportation, 2005Co-Authors: Sergio R Jaradiaz, Lourdes TrujilloAbstract:Cargo Handling in ports is a multioutput activity, as freight can arrive in many forms such as containers, bulk, rolling stock, or non-containerised general Cargo. In this paper, the operation of Cargo Handling firms in a Spanish port is analysed through the estimation of a multioutput cost model that uses monthly data on three representative firms located at the Las Palmas port. This permits the calculation of product specific marginal costs, economies of scale (general and by firm) and economies of scope, which help identifying optimal pricing policies and the potential cost advantages of increasing production.
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Technical and Allocative Efficiency in Spanish Port Cargo Handling Firms
2004Co-Authors: Ana Rodríguez-Álvarez, Lourdes TrujilloAbstract:Atkinson and Cornwell (1994) present two methods that permit the calculation of allocative inefficiency: the parametric approach and the error component approach. Fare an Grosskopf (1990) and Atkinson and Primont (2002) demonstrate that replacing the usual cost frontier with an input distance function can overcome the main drawbacks of the first approach by obtaining firm and time indexes of allocative efficiency. With regard to the second approach, the advantages of the distance function are developed in Rodriguez-Alvarez et al. (2004) which have dealt with the hypothesis in which the allocative efficiency is time-invariant and only varies across firms. In this paper we extend the analysis in the case in which the efficiency is firm and time-varying in both approaches. Moreover, we can calculate firm and time-varying technical efficiency and, separately, a measure of technical change. To do this, we present a distance system that is comprised of an input distance function and the share cost equations associated. We apply our methodology to a panel data using a sample of Cargo Handling firms in Spanish ports.
Sergio R. Jara-díaz - One of the best experts on this subject based on the ideXlab platform.
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Economies of scale and scope for Cargo Handling firms in Spanish ports
2020Co-Authors: Lourdes Trujillo, Sergio R. Jara-díazAbstract:Cargo Handling in ports is a multioutput activity, as freight can arrive in many forms like containers, bulk, rolling stock, or non-containerised general Cargo. Each type of movement involves the use of both common and specialised inputs. In this paper the operation of Cargo Handling firms in ports is analysed by means of the estimation of a multioutput cost function, using monthly data on three firms located at the Las Palmas port in Spain. Both size and traffic mix is first shown to be sufficiently diverse as to allow for a reliable estimation of a representative flexible (quadratic) cost function that permitted the calculation of product specific marginal costs, economies of scale (general and by firm) and economies of scope. Containerised Cargo is shown to present the smallest marginal costs for all firms, while non-containerised general Cargo has the largest. The largest firm exhibits constant returns while the smaller are still in the increasing returns zone, which suggests the convenience of increasing their scale of production. All firms exhibit economies of scope for every possible partition of the product set, which indicates the inconvenience of Cargo Handling specialisation by type. Prevailing average minimum prices are found to be of comparable magnitude (slightly larger) regarding the estimated marginal costs. This observed minimum price level suggests that they could be potential second best (Ramsey) prices needed to cover costs in the presence of increasing returns. For the covering abstract see ITRD E126595.
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Parametric estimation of inefficiency in Cargo Handling in Spanish ports
Journal of Productivity Analysis, 2008Co-Authors: Juan José Díaz-hernández, Eduardo Martínez-budría, Sergio R. Jara-díazAbstract:Port workers services have been usually heavily regulated and reserved exclusively for a special kind of workers, dockworkers, which seems to have been the cause of serious inefficiencies worldwide. During the eighties, law reforms have been introduced to solve this problem. In this paper we analyze and decompose efficiency in Cargo Handling operations in 19 Spanish ports from 1990 to 1998. The method chosen is that of the parametric estimation of both allocative and technical inefficiency using panel data and a quadratic cost function. Results show that although inefficiency has decreased overall, there has been over utilization of labor regarding capital, and technical inefficiency. This supports the need of further consideration of other aspects including competition.
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On the proper modelling of multioutput port Cargo Handling costs
Applied Economics, 2008Co-Authors: Sergio R. Jara-díaz, Beatriz Tovar, Lourdes TrujilloAbstract:Cargo Handling activities involve various heterogeneous outputs, e.g. general Cargo, containers, dry and liquid bulk and so on. These activities in ports, however, have been usually analysed using aggregate descriptions of output such as total tons moved. The main purpose of this article is to show that ignoring this heterogeneity may lead to two types of problems: (i) the underestimation of the relevance of key dimensions (i.e. marginal costs per product and economies of scope) and (ii) a bias in the estimates of the relevance of other dimensions (economies of scale). To do so, we rely on a unique new dataset on three Cargo Handling firms operating in a Spanish port between 1991 and 1999. We use it to estimate both a multi-output cost for these three operators, as well as an aggregate cost function. The policy conclusions are derived from an explicit and detailed comparison of these two sets of estimates.
Ana Rodriguezalvarez - One of the best experts on this subject based on the ideXlab platform.
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firm and time varying technical and allocative efficiency an application to port Cargo Handling firms
International Journal of Production Economics, 2007Co-Authors: Ana Rodriguezalvarez, Beatriz Tovar, Lourdes TrujilloAbstract:Abstract In this paper we present an econometric model to calculate both, the technical and the allocative efficiency in Cargo Handling firms in the port of Las Palmas (Spain). To achieve these aims, we estimate a system of equations consisting of a translog input distance function and cost shares equations. Using this procedure we can check the hypothesis in which, given technology and prices, terminal port inputs are not optimally allocated in the sense that costs are not minimized. The main contribution of this paper is to apply an empirical model that allows the unbiased estimation of allocative inefficiency of input use in two ways: an error components approach and a parametric approach. We also avoid the Greene Problem and allow allocative inefficiency to be systematic. Both size and traffic mix are first shown to be sufficiently diverse as to allow for a reliable estimation of a representative flexible (translog) function.
Beatriz Tovar - One of the best experts on this subject based on the ideXlab platform.
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On the proper modelling of multioutput port Cargo Handling costs
Applied Economics, 2008Co-Authors: Sergio R. Jara-díaz, Beatriz Tovar, Lourdes TrujilloAbstract:Cargo Handling activities involve various heterogeneous outputs, e.g. general Cargo, containers, dry and liquid bulk and so on. These activities in ports, however, have been usually analysed using aggregate descriptions of output such as total tons moved. The main purpose of this article is to show that ignoring this heterogeneity may lead to two types of problems: (i) the underestimation of the relevance of key dimensions (i.e. marginal costs per product and economies of scope) and (ii) a bias in the estimates of the relevance of other dimensions (economies of scale). To do so, we rely on a unique new dataset on three Cargo Handling firms operating in a Spanish port between 1991 and 1999. We use it to estimate both a multi-output cost for these three operators, as well as an aggregate cost function. The policy conclusions are derived from an explicit and detailed comparison of these two sets of estimates.
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firm and time varying technical and allocative efficiency an application to port Cargo Handling firms
International Journal of Production Economics, 2007Co-Authors: Ana Rodriguezalvarez, Beatriz Tovar, Lourdes TrujilloAbstract:Abstract In this paper we present an econometric model to calculate both, the technical and the allocative efficiency in Cargo Handling firms in the port of Las Palmas (Spain). To achieve these aims, we estimate a system of equations consisting of a translog input distance function and cost shares equations. Using this procedure we can check the hypothesis in which, given technology and prices, terminal port inputs are not optimally allocated in the sense that costs are not minimized. The main contribution of this paper is to apply an empirical model that allows the unbiased estimation of allocative inefficiency of input use in two ways: an error components approach and a parametric approach. We also avoid the Greene Problem and allow allocative inefficiency to be systematic. Both size and traffic mix are first shown to be sufficiently diverse as to allow for a reliable estimation of a representative flexible (translog) function.
Joshua P Newell - One of the best experts on this subject based on the ideXlab platform.
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life cycle emissions from port electrification a case study of Cargo Handling tractors at the port of los angeles
International Journal of Sustainable Transportation, 2012Co-Authors: Mansour Rahimi, Joshua P NewellAbstract:To reduce greenhouse gas emissions, ports around the world are considering using electric Cargo Handling equipment. To assess the benefits of the strategy, this study provides a comparative life-cycle assessment between diesel and electric yard tractors in a case study of the Port of Los Angeles. Results indicate a significant reduction in life-cycle emissions as the port shifts to electric vehicles and as the port's electricity supplier increases its use of renewable energy sources (e.g., wind and solar). The results also demonstrate that even with aggressive electrification strategies, the port's legislated reduction targets are not achievable by the year 2030.