It is a small world, or is it? A look into two decades of tourism system

Abstract

By adopting network science and Leiper (1979)’s tourism system conceptualization and by utilizing the UNWTO’s outbound tourism database, a portray of Global Tourism System (GTS) was constructed for the years between 1995 and 2018. GTS was then studied by using the measures of degree distribution, shortest geodesic distance, transitivity, and modularity analysis. Our results showed that GTS is a dense system (≈30%) which becomes denser with an average increase of 0.8% per year. Also while the system is on track to becoming resilient to economic crises, it is becoming vulnerable to other perturbations such as health crises. Furthermore, although GTS’s degree centrality is on the rise, its degree centralization is on a continuous decline. This continuous decline coupled with GTS’s disassortative nature are the indications of system’s decentralization. The findings of this study support the proposed hypothesis that GTS is best represented with Watts–Strogatz small-world network model. Nevertheless, the system’s in-degree and out-degree centrality measures follow two separate evolution regimes. From an out-degree perspective, we witness GTS’s transformation from a broad-scale small-world network to a single-scale one, while from an in-degree perspective, the system strictly follows a broad-scale small-world network. This means that although the small-world network is the best fitting model to GTS, the degree-preserved rewiring process is widely violated and therefore should be considered when modeling GTS. The disassortative nature of GTS and the lack of degree-preserved rewiring process have resulted in an obscure modularity structure which in turn generates a dynamic alternating pattern. Therefore, while, GTS demonstrates a static behavior with a fixed number of modules at all times, it has a dynamic destination membership in modules and destinations’ memberships constantly shift between modules.