In the context of the examples, I think "paper" is (rightly) being used as a synonym for "essay." Source: http://www.thesaurus.com/browse/essay.
Academics have a plethora of terms to describe their written outputs, e.g., journal article, conference paper, technical report, manuscript, ... Moreover, those terms can be used to describe a single body of work. For example, "I have submitted my manuscript to a conference. I'll publish it as a technical report, if it is accepted, to enable dissemination prior to publication of the conference paper. Hopefully, I'll publish an extended version as a journal article."