World citation and collaboration networks: uncovering the role of geography in science

TL;DR

This paper analyzes how geography influences scientific citation and collaboration networks, revealing that distance affects scientific interactions and that national research impact correlates with funding levels, despite technological advances.

Contribution

It provides a systematic analysis of geographic effects on scientific networks, demonstrating gravity law patterns and the impact of funding on research quality.

Findings

Citation and collaboration flows decrease with distance and follow gravity laws.

Research impact increases linearly with national R&D funding.

A threshold funding level of about $100,000 per researcher is needed for above-average impact.

Abstract

Modern information and communication technologies, especially the Internet, have diminished the role of spatial distances and territorial boundaries on the access and transmissibility of information. This has enabled scientists for closer collaboration and internationalization. Nevertheless, geography remains an important factor affecting the dynamics of science. Here we present a systematic analysis of citation and collaboration networks between cities and countries, by assigning papers to the geographic locations of their authors' affiliations. The citation flows as well as the collaboration strengths between cities decrease with the distance between them and follow gravity laws. In addition, the total research impact of a country grows linearly with the amount of national funding for research & development. However, the average impact reveals a peculiar threshold effect: the scientific output of a country may reach an impact larger than the world average only if the country invests more than about 100,000 USD per researcher annually.