A hybrid commodity price-forecasting model applied to the sugar-alcohol sector

Accurate price forecasting for agricultural commodities can have significant decision-making implications for suppliers, especially those of biofuels, where the agriculture and energy sectors intersect. Environmental pressures and high oil prices affect demand for biofuels and have reignited the discussion about effects on food prices. Suppliers in the sugar-alcohol sector need to decide the ideal proportion of ethanol and sugar to optimise their financial strategy. Prices can be affected by exogenous factors, such as exchange rates and interest rates, as well as non-observable variables like the convenience yield, which is related to supply shortages. The literature generally uses two approaches: artificial neural networks (ANNs), which are recognised as being in the forefront of exogenous-variable analysis, and stochastic models such as the Kalman filter, which is able to account for non-observable variables. This article proposes a hybrid model for forecasting the prices of agricultural commodities that is built upon both approaches and is applied to forecast the price of sugar. The Kalman filter considers the structure of the stochastic process that describes the evolution of prices. Neural networks allow variables that can impact asset prices in an indirect, nonlinear way, what cannot be incorporated easily into traditional econometric models.

On measuring quality of a probabilistic commodity forecast for a system that incorporates seasonal climate forecasts

Regional commodity forecasts are being used increasingly in agricultural industries to enhance their risk management and decision-making processes. These commodity forecasts are probabilistic in nature and are often integrated with a seasonal climate forecast system. The climate forecast system is based on a subset of analogue years drawn from the full climatological distribution. In this study we sought to measure forecast quality for such an integrated system. We investigated the quality of a commodity (i.e. wheat and sugar) forecast based on a subset of analogue years in relation to a standard reference forecast based on the full climatological set. We derived three key dimensions of forecast quality for such probabilistic forecasts: reliability, distribution shift, and change in dispersion. A measure of reliability was required to ensure no bias in the forecast distribution. This was assessed via the slope of the reliability plot, which was derived from examination of probability levels of forecasts and associated frequencies of realizations. The other two dimensions related to changes in features of the forecast distribution relative to the reference distribution. The relationship of 13 published accuracy/skill measures to these dimensions of forecast quality was assessed using principal component analysis in case studies of commodity forecasting using seasonal climate forecasting for the wheat and sugar industries in Australia. There were two orthogonal dimensions of forecast quality: one associated with distribution shift relative to the reference distribution and the other associated with relative distribution dispersion. Although the conventional quality measures aligned with these dimensions, none measured both adequately. We conclude that a multi-dimensional approach to assessment of forecast quality is required and that simple measures of reliability, distribution shift, and change in dispersion provide a means for such assessment. The analysis presented was also relevant to measuring quality of probabilistic seasonal climate forecasting systems. The importance of retaining a focus on the probabilistic nature of the forecast and avoiding simplifying, but erroneous, distortions was discussed in relation to applying this new forecast quality assessment paradigm to seasonal climate forecasts. Copyright (K) 2003 Royal Meteorological Society.

Cidade-paisagem : novas perspectivas sobre a preservação da paisagem urbana no Brasil

The edification of the landscape in the scientific and social field, in speech as in the method, is taken in this study as a complex process, from which were developed relationships of dominance on the perception of space, which persist strongly consolidated, since the genesis of the conceptual practice till its actual praxis. Historically, the landscape studies took place slowly, immersed in many questions, in face of the multiplicity of meanings that the concept offers. In the psyche, the notion of landscape is present since a long time ago, as an unconscious human being practice, even before any ideological hypothesis formulation. However its materialization in the social conscious will come only from painting, and specially with the perspective, through the technicity of the view, at first wandering the infinity, now ordained in a frame‟. Since then, the landscape is perceived according to the order of the view, as the equivalent of nature and beauty, assuming at the same time, an important symbolic value, since it is linked to mnemonic and subjective processes that the being build with the territory. The domain on this space-cognitive experience, characteristic of the contemporary, consolidates in the social imaginary, building consensus on the landscape, whose aesthetic references make a cultural appeal, very pertinent to the actual capitalist dynamics of production the space worldwide, mainly of the spectacle and commodification of cities promoted by the city marketing. In Brazil, this consensual ideology of the landscape surpass the social imaginary and also dominates the political imaginary, whereas the main instrument for preserving the landscape, Decree-law 25, from November 30, 1937, and its limit to those of exceptional value or remarkable feature. The analysis of the processes for putting under governmental trust for inscription of goods by the landscape value, reveals the dominant, if not exclusive, adoption of selection criteria related to aesthetic aspects. Abstain, therefore, from what the nation considers patrimony , other landscapes that, besides not having, at first, remarkable aesthetic value, play a crucial role as an inheritance from ancestor relations between man and space and pre- existing condition for the same present and future relations. From this historical background, the research seeks to transfer into contemporaneity, the ideological analysis of the concept and its relation with the building of the landscape in the collective imaginary, in order to recognize, in current practices to landscape preservation, as much this genesis, rooted in aesthetics, remains strongly consolidated, feeding the current dynamics of consumption and commodification of the city. Therefore, as preliminary conclusion, one can state that the identification of landscapes of different value, especially aesthetic, maintains and intensify the treatment of the city as an object, a standard‟ commodity to be sold / traded on the world market, in detriment of its recognition as a dynamic process that, even though inserted in the global context, develops specificifities and peculiarities, inherent to the production of space, as Lefebvre preconizes, that is, to the production of life, social product , as characteristic, dissent generator

Derek Jarman’s allegories of spectacle: inter-artistic embodiment

ABSTRACT - Derek Jarman was a multifaceted artist whose intermedial versatility reinforces a strong authorial discourse. He constructs an immersive allegorical world of hybrid art where different layers of cinematic, theatrical and painterly materials come together to convey a lyrical form and express a powerful ideological message. In Caravaggio (1986) and Edward II (1991), Jarman approaches two european historical figures from two different but concomitant perspectives. In Caravaggio, through the use of tableaux of abstract meaning and by focusing on the detailing of the models’ poses, Jarman re-enacts the allegorical spirit of Caravaggio’s paintings through entirely cinematic resources. Edward II was a king, and as a statesman he possessed a certain dose of showmanship. In this film Jarman reconstructs the theatrical basis of Christopher Marlowe’s Elizabethan play bringing it up to date in a successfully abstract approach to the musical stage. In this article, I intend to conjoin the practice of allegory in film with certain notions of existential phenomenology as advocated by Vivian Sobchack and Laura U. Marks, in order to address the relationship between the corporeality of the film and the lived bodies of the spectators. In this context, the allegory is a means to convey intradiegetically the sense-ability at play in the cinematic experience, reinforcing the textural and sensual nature of both film and viewer, which, in turn, is also materially enhanced in the film proper, touching the spectator in a supplementary fashion. The two corporealities favour an inter-artistic immersion achieved through coenaesthesia.

Orientalism and Imperialism in French West Africa. Considerations on travel literature, colonial tourism, and the desert as a “commodity” in Mauritania

In this article we intend to make a summary overview of the influence that literary production, originated under colonial mapping missions or later in travel writing, had in the construction and establishment of a discourse to advertise and promote tourism in Mauritania. To this end we will draw on travel narratives that are illustrative of different periods and that correspond in some way to discourses of otherness. In this specific case, such discourses relate to the “Moors” of the West African coast and were produced in various historical contexts. We will also consider the discourse present in the tourism promotion materials of the colonial period and we will demonstrate to what extent it can be engaged in a dialogue with 19th and 20th centuries’ Western colonial literature.

Price Transmission and Effects of Exchange Rates on Domestic Commodity Prices via Offshore and Currency Hedging

The framework presents how trading in the foreign commodity futures market and the forward exchange market can affect the optimal spot positions of domestic commodity producers and traders. It generalizes the models of Kawai and Zilcha (1986) and Kofman and Viaene (1991) to allow both intermediate and final commodities to be traded in the international and futures markets, and the exporters/importers to face production shock, domestic factor costs and a random price. Applying mean-variance expected utility, we find that a rise in the expected exchange rate can raise both supply and demand for commodities and reduce domestic prices if the exchange rate elasticity of supply is greater than that of demand. Whether higher volatilities of exchange rate and foreign futures price can reduce the optimal spot position of domestic traders depends on the correlation between the exchange rate and the foreign futures price. Even though the forward exchange market is unbiased, and there is no correlation between commodity prices and exchange rates, the exchange rate can still affect domestic trading and prices through offshore hedging and international trade if the traders are interested in their profit in domestic currency. It illustrates how the world prices and foreign futures prices of commodities and their volatility can be transmitted to the domestic market as well as the dynamic relationship between intermediate and final goods prices. The equilibrium prices depends on trader behaviour i.e. who trades or does not trade in the foreign commodity futures and domestic forward currency markets. The empirical result applying a two-stage-least-squares approach to Thai rice and rubber prices supports the theoretical result.

Primary Commodity Prices: Co-movements, Common Factors and Fundamentals

The behavior of commodities is critical for developing and developed countries alike. This paper contributes to the empirical evidence on the co-movement and determinants of commodity prices. Using nonstationary panel methods, we document a statistically significant degree of co-movement due to a common factor. Within a Factor Augmented VAR approach, real interest rate and uncertainty, as postulated by a simple asset pricing model, are both found to be negatively related to this common factor. This evidence is robust to the inclusion of demand and supply shocks, which both positively impact on the co-movement of commodity prices.