A Modularity Decomposition Model Of Evolving Input-Output Sectorial Structure

This paper builds on the network paradigm to model the evolving input-output (IO) economic structure of Greece into a multiplex network (GION) and unveils structural changes during the period 2005-2015, with reference to the 2008 economic crisis. The results illustrate that the GION resembles to a composition of windmill graphs, it is more clustered at the neighborhood scale, with a tertiary sectorial orientation, a solid performance of the trade and transportation industries, inelastic demand in energy-related economic activities, a neutral profile in communication and manufacturing relevant activities, insufficient connectedness of education, and vulnerable in the construction-related economic activities and the public sector. A major finding describes that the tourism industry is dynamic more due to its dependence on the supportive economies than the intrinsic industrial productivity. The time-series and community detection analysis provide insights into distinguishing three stages in the GION’s evolution: the pre-crisis period (2005-2007), with a centralized topology in terms of outgoing connectivity and degree inequalities; the on-crisis period (2008-2010), with a decentralized topology and a tendency to reduce degree inequalities; and the post-crisis period (2011-2015), with a new state of centralized topology illustrating a recovery process. The analysis also reveals a diversified configuration in the Greek economy compared to the three-sector classical breakdown, composed of “tourism” and “transportation and energy” sector-like components, and the traditional secondary and tertiary sectors. Overall, the analysis shapes a “balloon” waiving pattern in the network evolution and reveals solid and fragment-favorable economic interactions in the GION’s structure, promoting network analysis to the input-output structural modeling.