Monday, February 16, 2015

Crosscitations between patent families

Even if Patstat provides only citation file by publications, lots of scientific literature uses citations across patent families as a more relevant measure for knowledge spillovers, patent value etc. since, compared to sheer publication based citation count, it normalizes the data across patent offices.

Nevertheless two caveat should be taken in count when using patent family based citation measures

1) Cross citation may happen
consider example below: all is fine until we look at publications. When using docdb families a crosscitation arises.



citing
cited
citing fam
cited fam
US7507793 
US7534577
26973151
26947173
US7534577
US7402400
26947173
26973151

These cases are about 581779 (0,5% of total citations).

 2) self citations are not uncommon

262781 citations @ 2014b edition are within the same docdb family (0.2 %)



citing
cited
citing fam
cited fam
US7534577
WO02064631
26947173
26947173