Submitted by Mario BC (mario@bc.ufrpe.br) on 2018-05-14T14:17:21Z No. of bitstreams: 1 Cristiane Rocha Albuquerque Lima.pdf: 1533326 bytes, checksum: 9e87bf8eb0c81a89231a288c86544a33 (MD5) / Made available in DSpace on 2018-05-14T14:17:22Z (GMT). No. of bitstreams: 1 Cristiane Rocha Albuquerque Lima.pdf: 1533326 bytes, checksum: 9e87bf8eb0c81a89231a288c86544a33 (MD5) Previous issue date: 2017-08-24 / As human beings developed agriculture, human civilization was modified. Innovations in the world’s agriculture have turned this activity into a major energy drain. In this way, the agricultural sector become heavily dependent on energy prices through the cost of transport, fertilizers, pesticides and food processing. Energy prices also affect the food market by inducing policies that divert food crops to the production of biofuels. The relationship between oil prices and agricultural commodity (feedstock) prices has attracted a considerable attention in the last years, resulting in an extensive scientific literature. The most important link between the energy and food markets is the production of biofuels (ethanol and biodiesel). The increased production of biofuels and its competition with food production raises the need for a deeper understanding of the relationship between the two markets. The interaction between biofuel and food markets in the US and Europe has been extensively studied in the last years. On the other hand, the Brazilian market for sugar cane and ethanol has received much less attention. In the present study, the interaction between the Brazilian energy and food markets was investigated from the point of view of Econophysics. The weekly series of prices of oil, ethanol and sugar for the period 07/07/2000 to 03/24/2016 were analyzed using the methods Detrended Cross Correlation Analysis (DCCA) and its recently proposed modification Detrended Partial Cross Correlation Analysis (DPCCA) which was developed to quantify the intrinsic cross-correlations between two non-stationary time series. The results show the existence of long-range cross-correlations in time series of volatility of oil, ethanol and sugar indicated by the value of DCCA exponent which was greater than 0.5. The intrinsic cross-correlations revealed by the DPCCA are positive for ethanol-sugar and oil-sugar volatility series, and negative for oil-ethanol volatility series, suggesting that the interactions between energy commodity markets and agricultural commodity market are different from the interactions within the energy commodities market. / Na medida em que os seres humanos desenvolveram a agricultura, a civilização humana foi modificada. As inovações na agricultura mundial transformaram esta atividade em um grande sorvedouro de energia. Consequentemente, os preços da energia aumentaram os custos dos transportes, fertilizantes, pesticidas e do processamento de alimentos. O mercado de alimentos também foi afetado pelos preços da energia através de políticas que passaram a desviar as culturas alimentares para a produção de biocombustíveis (etanol e biodiesel), criando assim uma importante ligação entre estes mercados e levantando a necessidade de uma compreensão mais profunda desta relação. Nos EUA e Europa, a interação entre os forma, a relação entre os preços do petróleo e os preços das commodities (matériasprimas) agrícolas tem atraído uma atenção considerável nos últimos anos. Por outro lado, o mercado brasileiro de cana-de-açúcar e etanol tem recebido muito menos atenção. No presente estudo, o objetivo foi investigar correlações intrínsecas de longo prazo entre os mercados brasileiros de energia e de alimentos, utilizando as técnicas da Econofísica. Foram analisadas as séries semanais de preços de petróleo, etanol e açúcar durante o período de 07/07/2000 a 24/03/2016 usando os métodos Detrended Cross Correlation Analysis (DCCA) e sua modificação recentemente proposta Detrended Partial Cross Correlation Analysis (DPCCA), desenvolvida para quantificar as correlações cruzadas intrínsecas entre duas séries temporais não estacionárias. Os resultados mostram que existem correlações cruzadas de longo alcance nas séries temporais de volatilidade do petróleo, etanol e açúcar, indicadas pelo valor do expoente DCCA maior que 0,5. As correlações intrínsecas reveladas pelo DPCCA são positivas para as séries de volatilidade de açúcar-etanol e de açúcar-petróleo, e negativas para as séries de volatilidade de etanol-petróleo, indicando que as interações entre os mercados de commodities do segmento de energia e commodities agrícolas são diferentes das interações dentro do mercado de commodities do segmento de energia.