https://seekerblog.com/2006/01/31/the-murray-gell-mann-amnes...
For instance, a poli-sci major writing about a scientific/tech topic will likely get a lot of things wrong. However, the same journalist might likely have a lot of interesting things to write about international politics, because that's what his background is about.
that being said, I don't know how much journalist writing about politics have studied it in the past.
https://books.google.com/books?id=KUyOAgAAQBAJ&pg=PA42&lpg=P...
not that it really matters, i have an econ degree but wouldn't call myself an economist by any stretch.
the real issue, at least in the US, most news is really just either direct or indirect PR. curiously, i think 'X writer' is the term you are looking for. i.e., someone with a background in technology or fashion that reports on things is more likely to be called themselves a 'tech writer' or 'fashion writer'. it's almost like real experts don't even want to be called journalists. i certainly wouldn't.
i've found that you're much more likely to find accurate reporting in industry-specific media rather than general media, because then at least the sources of funding and agenda are pretty clear.
eg. Bloomberg, The Economist, The Wallstreet Journal, The Financial Times
Probably because it's the last industry where people are willing to fork over money for reliable news