The Sharing Economy is an innovative social, economic and technological paradigm which is shaping worldwide production and consumption patterns of many industries. Its strength relies on factors of competitiveness such as the use of idle capacity, temporary access to resources without transfer of ownership, the flexibility and adaptability of its models, and the participation of a growing number of players allowed by peer-to-peer digital platforms. From the management perspective, the conditions for lasting competitiveness lies on sustainability, the paradigm integrating the supply, demand, and technological dimensions in a holistic, or ecosystem, perspective. Tourism is among the industries making extensive use of sharing digital platforms and experiencing changes that foster the sustainability debate. The PhD Thesis aims to investigate the relationships between competitiveness and sustainability in the tourism and hospitality accommodation industry in the Sharing Economy Era. Its investigation is multifaced and is addressed through three studies adopting a post-modernist perspective that builds on qualitative approaches and strategies for data collection and analysis. The Part I of the Thesis explores the Sharing Economy concept’s evolution and the sustainability issues through an in-depth review of the literature. Results reveal the leading economic-technological evolution of the paradigm over the social one, and its dual links with sustainability in relation to the extensive use of peer-to-peer digital platforms. Therefore, the evolution of the Sharing Economy activities have shown that today competitiveness is built on the interactions of an ever-increasing number of actors and factors, both off-line and on-line, within a complex ecosystem for the creation of – shared – value. The tourism industry strongly challenges this relationship between extended competition and sustainability. The Part II evaluates the competitiveness model and its evolution during the Sharing eTourism Era in the tourism and hospitality accommodation sector introducing an ecosystem perspective for the creation and distribution of shared value. Specifically, it investigates how the non-traditional and informal tourist services have affected the structure of the industry and have altered the competition among the actors, through semi-structured in-depth interviews. Results show that competitiveness is given by the balance among the complex interactions of internal and external ecosystem’s actors and factors. On a micro level this imply that businesses must adopts an ecosystem vision compensating for negative externalities which translate into the adoption of Business Models promoting sustainability for the creation of sustainable shared value. Therefore, the Part III investigates through the use of an illustrative case study how peer-to-peer digital platforms in the tourist accommodation service can boost profitability while strengthening economic, social and environmental sustainability by applying the innovative Business Model for Sustainability. The research sheds light on the complex Sharing Economy literature and lays the theoretical foundations for the implementation of managerial strategies aimed at promoting extended sustainable competition-cooperation.

Open-source software (OSS) ecosystems, defined as environments composed of package managers and programming languages (e.g., NPM for JavaScript), are essential for software development and foster collaboration and innovation. Although their significance is acknowledged, understanding what makes OSS communities healthy and sustainable requires further exploration. This thesis quantitatively assesses the health of OSS projects and communities within the NPM, PyPI, Maven, and RubyGems ecosystems. We explore five research questions addressing project standards, community responsiveness, contribution distribution, contributor retention, and newcomer integration strategies. Our analysis shows varied documentation practices, insider engagement levels, and contribution patterns. Our findings highlight both strengths and different areas for improvement across ecosystems. For example, RubyGems excels in the adoption of project documentation and exhibits the most even distribution of contributions among all contributors, including highly active contributors. and a very responsive community, but it needs to improve contribution retention and attract newcomers to the projects. Meanwhile, NPM and Maven show a trend toward getting new contributors, characterized by a high ratio of individual contributions. They need to better adopt a code of conduct, pull request templates, and increase the number of active contributors in a project. This thesis offers insights to developers and maintainers on how to strengthen ecosystems and support vibrant communities effectively