Why some articles are free (PMC) and others are not

[samman1994]

Hello everyone,

Just a general question that has popped up as I've been looking at research articles on pubmed. Some articles are in a journal (e.g. ACS) but also on pubmed for free (PMC) [free access]. I thought originally, ok maybe after a few years pass they say lets put it out free, but I've seen old articles not for free, and new articles for free. I'm just curious (I have never personally published a paper myself), why some papers are free and some are not. Does the PI publish and allow it to be read for free? Does pubmed select some articles to be shown for free? How does this work? 

[freckledgenes]

There are a variety of reasons. I believe research that is NIH-funded has to be open access. Also, many journals allow authors to pay an extra fee for immediate open access. Some journals also have policies on articles becoming open access after a year or more. There might be other factors I'm unaware of as well.

[samman1994]

Ah I see,guess that makes sense. Thank you for the reply!

[cowgirlsdontcry]

Are you doing research on a university library database? If you run into articles on those that aren't free to download, it's because the university does not subscribe to the journal it's published in. Students in the humanities run into this a lot, unless they are at a huge university that subscribes to all of the academic journals. As an MA student, I would see an interesting article, but it wasn't available. I would follow the link and end up at the journal site, then get a message that my university did not subscribe to the journal. With that said, I could order a no cost copy through ILL. At my current university, the arts/sciences are combined in a college and share a library. If you need something from the medical library, you either have to trek over to the medical school or you have to go through their databases, which we have also have access to.

[Eigen]

NIH requires that all pre-prints be uploaded to PubMed within 1 year of publication, or you lose your grants. 

They don't pay the journals for open access, rather, they go around copyright- you don't submit the exact same article to NCBI as you do to the journal- you submit a pre-print. It's a cheap way of sidestepping copyright, but since the vast majority of research in some fields is funded by the NIH, no journal wants to go against it, so it works out well. Otherwise, that journal would just stop getting NIH funded research published there. It's one of the few cases where the journal ends up being strong-armed, rather than doing the pressuring.

[samman1994]

1) This is for general. I don't even use my schools proxy. Sci-hub gives me access to all the journals, whereas my school does not. 

2) That's what I thought, but I've also found articles from 2014, or even 2001 that are not for free on pubmed. That's why I was confused, it didn't seem very consistent in regards to: older articles free, newer ones go to journal.