Did you have some sort of statistics requirement?
I went over to Notre Dame’s website (arrived at via websearch of “Political Science”). As far as I can tell, “Political Science” and “Government” are synonyms insofar as university departmental titles are concerned. Notre Dame’s faculty in their Department of Political Science are divided into 5 headings: they are American Politics, Constitutional Studies, Comparative Politics, Political Theory and International Relations. I can imagine the methods of science being used or not being used in any of them. That said, historical and legal inquiry are legitimate endeavors and can be scholarly.
The OP: incidentally, the authors of the study use the term “Oligarchy” exactly once in the text. And that’s inside their literature review: it’s another researcher who use that term.
Pray tell: describe a place and age (say 40+ years) where the elite did not run the show and living standards grew substantially. In rhetorical (not scientific) terms the US has always been an oligarchy. And it’s usually succeeded in delivering a higher standard of living for the grandkids.
Oligarchy is the way of the world. This isn’t ancient Rome, the USSR or any number of toxic oligarchies of the past. And while blustering about corporations will give you some electoral traction, it will turn off the vast number of potential swing voters who depend upon Big Corp for their livelihood. The only thing the Greens ever did for the US is deliver their leader, GWBush, to the Presidency. Nobel Laurette Al Gore wasn’t pure enough for them.
Attacking the Koch Bros is another matter: apparently that polls well. Science!