In this paper we examine the extent to which the relationship between energy consumption and real GDP can be affected by an effective economic development policy based on industrialization. The Spanish Stabilization and Liberalization Plan of 1959 is regarded as a “natural experiment” that is especially interesting for our purposes. To explore long-run causality and possible changes in its direction, we have exploited statistical information for a long period (1900-2008). We applied a movingwindow regression procedure based on the augmented vector autoregressive methodology of Toda and Yamamoto (1995). Causality results are highly sensitive to the industrialization process. For the sub-period preceding the development policy we consistently found greater support for the “conservation hypothesis”. This contrasts sharply with the set of results from the data belonging to the subsequent sub-period, where evidence is in favor of the “growth hypothesis”. Financial support from the Spanish Ministry of Economy and Competitiveness (ECO2011-28155) and the Generalitat Valenciana (VALI+D, ACIF/2010) are gratefully acknowledged.