The theory of storage and the volatility in commadity markets

• Autor(a) principal: Albuquerque, Thiago de Orlando e
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Institucional do FGV (FGV Repositório Digital)
• Texto Completo: http://hdl.handle.net/10438/4326
• topic: Volatility; Commodities; Convenience-yield; Economia; Bolsa de mercadorias - Preços; Preços - Previsão; Estoques

This paper extends the methodology of Fama and French (1988) to test the hypothesis described in the theory of storage that the marginal convenience yield on inventory falls at a decreasing rate as inventory increases. As Samuelson (1965) describes, the theory implies that spot and futures price variations will be similar when inventories are high, but futures prices are less variable than spot prices when inventory is low. I test the hypothesis by examining the relative variation of spot and futures prices for WTI crude oil, aluminum and copper based on the Fama and French (1988) method that uses the interest-adjusted basis as a proxy of high and low inventories. Results for the metals are, in general, consistent with the theory of storage, even testing for subperiods, including the boom and burst in the prices of commodities occurred in 2005-2008. For the price of oil, however, some of the results do not hold, especially for the longer contracts, showing that other factors rather than stocks, supply and demand (e.g. speculation) may be driving spot and/or future prices.