Historical analysis of energy intensity of Spain:: From a "conventional view" to an "integrated assessment"

Understanding the relationship between the Gross Domestic Product (GDP) and the throughput of matter and energy over time in modern societies is crucial for understanding the sustainability predicament as it is linked to economic growth. Available data on changes in energy use and economic performance in Spain (over the period 1960-1996) shows that Spain has been increasing its energy intensity during this period contrary to the hypothesis of an "inverted-U shaped curve of intensity of use." Will this increase be followed soon by a decrease! Or rather should we look for alternative explanatory hypotheses and study changes in the dynamic energy budget of Spain as movements between 'attractor points'? If this is the case, what are the main mechanisms generating such a behaviour? Three nonequivalent methods of analysis complementing each other are used to deal with these questions.