Identifying technological trajectories in the mining sector using patent citation networks
Enrico Alessandri
#2021-048
This paper uses patent citation networks to study technological change
in the mining industry between 1970 and 2015. The analysis is undertaken
at both the aggregate level by jointly considering all mining-related
technological fields, and at the micro-level of patents in nine
sub-fields, representing specific technological "sub-trajectories".
Consistent with previous literature focused on other technological
domains, we find that innovation patterns in the mining sector are
"technology bounded", i.e. largely shaped by patenting activities
carried out in a very limited range of mining technological fields, even
though we detect a shift from exploration to environmental mining
technologies (emergence of a new technological paradigm). In addition,
we examine two aspects of technical change that have been largely
disregarded in extant research: the geographical patterns of inventive
activities and the role of key applicants in such patterns. We show that
core mining patents and leading inventors involved originate almost
exclusively from the US, so that trajectories appear to be heavily
"geographically bounded", revealing that developing resource-abundant
countries lag behind the technological frontier in mining. Moreover,
only a few applicant firms are responsible for most inventive activities
reflecting a highly concentrated oligopolistic structure, hence
characterising trajectories as "applicant bounded". Similar results are
observed at the level of sub-trajectories, although with some relevant
exceptions, hence suggesting that a substantial heterogeneity exists
within the industry and across mining-related technologies.
JEL Classification: O31, 033, L72, F23, R11
Keywords: Technological trajectories, Technological sub-trajectories,
Mining technologies, Geography of innovation, Patents, International
technological frontier