Since the United Nations approved the eight Millennium Development Goals in 2000 and, 15 years later, the 2030 Agenda for Sustainable Development and its 17 Sustainable Development Goals (SDGs), the highest political institutions in the world have not stopped worrying about achieving the sustainability of the planet. Also in 2015, the European Commission prepared the European Union Action Plan for the Circular Economy, seeking a transition towards a less linear economy, in which products, materials, and resources are kept in the system for as long as possible and in which the generation of waste is minimized.Since then, the European Union has continued issuing reports and communications to accelerate this process in search of a circular economy, making continuous references to the fact that, through circular economy initiatives, the SDGs would be fulfilled. In this context, the objectives of this paper are 1) to determine, through exploratory factor analysis and correlation analysis, whether there is a statistically significant relationship between circular economy initiatives undertaken in the EU and compliance with the SDGs; 2) to check, through a cluster analysis, if there are homogeneous groups of countries worldwide in terms of compliance with the SDGs; and 3) using this same technique, to check whether the countries that make up the EU achieve similar results in terms of compliance with the SDGs.

The European Union (EU) is trying to accelerate the transition from the current linear economy to a circular economy (CE). In fact, the CE is considered a tool to attain sustainable development goals (SDGs). In this sense, this paper aims at analysing the interaction between the CE and SDGs in the context of the new 2030 Agenda and the European CE strategy; thus contributing to the scarce empirical literature that links the potential of the European CE strategy to the achievement of the SDGs set by the 2030 Agenda. Three specific research questions have been formulated. First, could the objectives defined in the 2030 Agenda be considered homogeneous, and could they uniquely measure the concept of sustainability? Second, are there significant correlations between the implementation of a CE in the EU and the SDGs? Finally, is the behaviour of the 28 countries that make up the EU homogeneous in terms of the results of the initiatives aimed at the implementation of a CE? From these questions, nine hypotheses are put forward concerning the possible relationships between a CE implementation and the fulfilment of SDGs in the EU. Using a correlation analysis, an exploratory factor analysis, and a cluster analysis, it has been demonstrated that (a) SDGs do not univocally measure the concept of sustainability; (b) there are significant relationships between CE and SDGs in the EU; (c) the behaviour of these European countries is not homogeneous.

This study focuses on discovering sustainable practices and possible innovative practices according to factors of Contingency Theory. In order to achieve this, a qualitative approach has been conducted. The study analyses 24 independent hotels. Semi-structured interviews were used in this study and conducted in person with the top managers at each hotel. The results show that, in accordance with Contingency Theory, the organizational behaviour is determined by the environment in which the hotel operates, the size of the establishment, where large- and medium-sized hotels are more committed to sustainable development, the environmental technology adopted and implemented by the hotel, and the main type of clientele, with hotels aimed at business travellers who show greater attention to the environment than those aimed at leisure travellers, mainly associated with socio-cultural values. The factors that were not completely decisive in the results analysed were the age of the hotel and the sex of the hotel owner. Considering the achieved results, this study may also contribute to identifying the most sustainable hotels and can help hotel businesses understand and reap the benefits of following a sustainable path.

La actualmente denominada economía colaborativa, como modelo económico y social en el que los agentes comparten, de manera temporal, activos, bienes y servicios, en muchos casos infrautilizados, a cambio de dinero o de otros servicios, utilizando plataformas on line, está creciendo de manera imparable y se está introduciendo en sectores tradicionales como la producción de bienes y la prestación de servicios profesionales y financieros y, muy especialmente, en el sector turismo, en concreto en los subsectores de alojamiento y de transporte. Sin embargo, no todas las actividades que actualmente se están circunscribiendo al ámbito de la economía colaborativa en realidad pertenecen a ella. En realidad, parte de estas actividades son, únicamente, nuevos modelos de negocio que poco tienen de colaborativo. Ante esta ambigua delimitación de lo que es realmente economía compartida o colaborativa y lo que son, simplemente, nuevos modelos de negocio, ha surgido una fuerte oposición por parte de las empresas que siguen los modelos tradicionales, las cuales están siendo apoyadas por los gobiernos centrales y locales de algunos países de la Unión Europea, como es el caso de España, que están tratando de limitar la implantación de estos nuevos modelos. Frente a esta situación, la Comisión Europea está apostando por su desarrollo, marcando unas directrices orientadas a incentivar e impulsar estos nuevos modelos relacionados con la economía colaborativa.

The increasing relevance of air transport as a contributor to climate change requires the development of emissions reduction technologies in a socio-economic and cultural context, where demand and air traffic have traditionally held sustained growth rates. However, the irruption of COVID-19 in 2020 has had an enormous negative impact on air travel demand and traffic volumes. Coincidentally, during 2020, new technology proposals for emissions reduction based on use of hydrogen and synthetic fuels have emerged from the aviation stake holders. By following a novel approach connecting the analysis of expectations of technology developments and their deployment into the fleet to market constraints, this study discusses how, even considering the new technology proposals and even if the COVID-19 has led to a completely different scenario in tourism and aviation, the air transport energy paradigm will remain unchanged in the upcoming decades as a consequence of market constraints, aircraft complexity, compliance with safety requirements, and extended life cycles. In this frame, aviation needs to keep on pursuing the abatement of its emissions while managing social expectations in a realistic manner and leaning on compensation schemes to achieve emissions contention while new technologies become serviceable in the longer term.