https://www.nber.org/papers/w17800
Authors. Borjas, G. J. & Doran, K. B
Venue. NBER Working Paper 17800 landing page (published in the Quarterly Journal of Economics 127(3), 2012)
How the Institute flags it
frontier 1 time established 1 time
This source carries more than one flag across the corpus. That is not an inconsistency to resolve: the same work can be established evidence for one claim and frontier evidence for another, and the flag belongs to the use rather than to the source.