Decision Making in Networked Systems

Living in a networked world, human agents are increasingly connected as advances in technology facilitates the flow of information between and the availability of services to them. Through this research, we look at interacting agents in networked environments, and explore how their decisions are influenced by other people\u27s decisions. In this context, an individual\u27s decision may be regarding a concrete action, e.g., adoption of a product or service that is offered, or simply shape her opinion about a subject. Accordingly, we investigate two classes of such problems. The first problem is the dynamics of service adoption in networked environments, where one user\u27s adoption decision, influences the adoption decision of other users by affecting (positively or negatively) the benefits that they derive from the service. We consider this problem in the context of User-Provided Connectivity , or UPC. The service offers an alternative to traditional infrastructure-based communication services by allowing users to share their home base connectivity with other users, thereby increasing their access to connectivity. We investigate when such services are viable, and propose a number of pricing policies of different complexities. The pricing policies exhibit differences in their ability to maximize the total welfare created by the service, and distributing the welfare between different stakeholders. The second problem is the spread of opinions in a networked environment, where one agent\u27s opinion about an issue, influences and is influenced by that of other agents to whom she is connected. We are particularly interested in the role that people\u27s adherence to specific groups or parties may play in how final opinions are formed. We approach this problem using a model of interactions inspired by the Ising spin-glass model from classical Physics. We consider two related but distinct settings, and show that when party memberships directly influence user interactions, even slightest statistical partisan biases result in partisan final outcomes: where everyone in a party shares the same opinion, opposite to that of the other party. On the other hand, if party membership plays an indirect role in biasing agent interactions, then there is room for intra-party heterogeneity of opinions

The Socio-Technical Dynamics of Renewable Energy Policies in Germany

Growing environmental concerns and human-caused climate change increase the pressure on policymakers for rapid action to transform how societies convert energy, produce goods, or transport freight. Innovation and technological progress may contribute to such transitions. However, technological change is hard to predict, requires time, and may be laden with political conflicts. Although more sustainable technologies are available, incentivizing demand and deployment are crucial to accelerate transitions. As transformations develop over decades, understanding the temporal dynamics of policies is critical for governance. In Germany, the renewable energy act incentivizes the deployment of renewable energy technologies by remunerating electricity fed into the common grid. This dissertation assesses how socio-technical developments of solar and wind energy conversion technologies and the renewable energy act interactively shaped each other. Drawing on frameworks such as technological innovation systems, legitimacy, framing, and policy feedback, the contents of 16,485 newspaper articles and additional empirical studies were scrutinized. Combining methods from natural language processing, machine learning, and statistics, this thesis develops text models to assess changes in content and sentiment in large corpora over time. Three studies focus on the shifts in media framing of the German renewable energy act, the underlying co-evolution of technological and policy processes, and the development of the legitimacy of wind power. The results confirm that renewable energy deployment and policy are contested with varying intensity over time. Where change ought to occur, non-linear dynamics of innovation and technology uptake, growing policy costs, economic interests of incumbents, and technology side effects increasingly complicate policymaking over time. The early phases of the renewable energy act were shaped by positive expectations toward renewable energy technologies, which later shifted towards an emphasis on policy costs. The findings highlight the importance of the prosperity of underlying innovation systems as supporters of policy ambition and maintenance over time. However, policy costs and side effects must be managed effectively to withstand increasing contestation. These results may contribute to advancing the successful governance of sectoral transitions likely to unfold over several decades