The production and diffusion of knowledge: essays on Science, Technology, and Proximity

The mainstream recipe for long-run economic prosperity rests upon generating novel ideas and turning them into marketplace innovations. Such innovations increase productivity, and an increase in productivity begets economic growth. Nonetheless, uncovering the roots, mechanisms, and consequences of the production and diffusion of ideas remains a crucial challenge. Ideas and knowledge are “public goods” that markets fail to deal with, causing distortions in the level and direction of research efforts. For instance, insufficient resources support fundamental research on crucial issues such as climate change. Fortunately, knowledge flows following patterns that can now be tracked by exploiting big data, combined with network and data science tools. Accordingly, this dissertation takes a data-driven perspective to provide new evidence on how social, technological, and geographical proximity affects the production and diffusion of knowledge. The first essay provides evidence that centrality in the inter-sectoral knowledge space positively affects the competitiveness of industries, but only national knowledge flows have a significant impact. We shift the emphasis of the analysis from the bilateral knowledge flows that characterize industrial relationships to the position of an industry in the entire intersectoral knowledge space. We collect patent data on 14 manufacturing industries in 16 OECD countries over the period 1995–2009 to track down inter-sectoral flows, and then we investigate whether the relative position of an industry affects its international competitiveness. The analysis suggests that centrality in the inter-sectoral knowledge space positively affects industries’ export market shares. Furthermore, national-level knowledge flows’ impacts on international competitiveness are stronger than international ones. Industries that can intercept knowledge flows outperform their foreign counterparts. Interestingly, this is true as far as national flows are concerned: geographical boundaries still limit the transmission of tacit knowledge. Next, the second essay shows that knowledge and social proximity drive scientists’ research portfolio diversification, and social relationships become crucial when scientists move far from their core specialization. By looking at the research output of roughly 200k physicists and using bipartite networks, we derive a measure of topic similarity and a measure of social proximity to investigate to what extent knowledge and social proximity shape scientists’ research portfolio diversification. We find that scientists’ strategies are not random and significantly affected by both measures. However, social relatedness stands out in explaining research diversification, suggesting that science is an eminently social enterprise. In addition, a significant negative interaction between knowledge and social relatedness signals that the farther scientists move from their specialization, the more they rely on collaborations. Finally, the third essay aims at quantifying knowledge spillovers stemming from research efforts in “Negative Emissions Technologies” (NETs), deemed as one of the leading potential solutions to tackle global warming. As of today, however, NETs hardly represent fully developed technologies to be deployed at scale. By looking at scientific articles, patents, and policy documents, we quantify the impact of NETs within and beyond the scientific realm. Our results suggest that knowledge spillovers are non-negligible for NETs research. Yet, the impact of different NETs varies greatly within science, and Direct Air Capture (DAC) is the option that generates more impact beyond the academic world (measured by citations coming from patents). Finally, we also apply network analysis to identify research hubs that can support future collaborations. Science and technology policy will play a crucial role in shaping our response to crises and societal challenges, such as global health issues or climate change. The essays collected in this work contribute to the literature by offering novel insights into how scientific and technical knowledge flows across our economies and societies, including policy-relevant recommendations.