Abstract
This paper empirically analyzes the indebtedness of the main companies in the Spanish hotel industry. In particular, it introduces a method to analyze the structures and dynamics of the largest companies in this sector. The method combines the Pearson correlation coefficient with the nearest neighbour single linkage clustering algorithm (Mantegna, R. N. (1999). Hierarchical structure in financial markets. The European Physical Journal B, 11, 193–197). The Pearson correlation coefficient determines a metric distance between two different multidimensional time series that is then used to construct a Minimal Spanning Tree. From this tree, an ultra metric distance that is used to derive the Hierarchical Tree can be computed. From the analysis of the time series data of companies included in the SABI, or the Iberian Balance Sheet Analysis System 2005, it is possible to derive a hierarchical organization of the Spanish hotel firms. In particular, different dynamic clusters of companies, which correspond to their common production and indebtedness strategies, can be detected.