Item — HN Reader

“Our analysis indicates that, in 2013, 36% of citations were to articles that are at least 10 years old and that this fraction has grown 28% since 1990,”

Put another way, in 1990, 28% of citations were to articles that are at least 10 years old. (28*1.28 = 36). So, in 1990 a significant number of citations were already older papers.

I wonder if there is a way to weight individual citations within each work (e.g., by age of the paper cited?) to further strengthen the signal.

Also, at some point, the fraction of old papers cited should approach 0% (the fields had to start sometime). It would be interesting to reproduce this analysis for time bins which are older. I presume one would find that the fraction of citations that are to papers 10 years or older would be a monotonically increasing function of time. So one then needs to ask if this increase is due to better access to articles or if it is simply due to there being a larger body of work which is older than 10 years?

1 comments

Fields generally doesn't start - they branch off as a specialization of something else. So no, there will be no 0 % unless you go really far back.

Right, the aside about "starting" was hyperbole. And I purposefully said "approach 0%", not "be 0%".

As an example, there are astronomy publications stretching over more than 100 years, which could be used in a study like this. Analyzing the citation data in 10 year bins may be able to see if the increase in citations to "old" papers (> 10 years old at the time of the citation) is due to an increased corpus of papers (the citation fration should rise with time, likely related to the total number of prior papers in existence) or due to improved acess to older papers (the change in the past 10–20 years should be significantly greater than in the previous time bins).

Indeed, and arguably, even if you go really far back, even fields like physics and mathematics spawned out from philosophy. Physics was originally known as "natural philosophy" for example. Biology came into existence independently several places, but often it was considered to be a part of Theology, and a study of Gods creation. Hardly any field except philosophy and theology has started as anything other than a specialization of something else.