To speed up publication, an article may be published ahead of the issue that would otherwise have contained it. AUP calls such articles “Fast Track”. AUP does this for these journals
Curious case: article has a different fast track DOI than “normal” DOI so that two version now live on the platform:
https://www.aup-online.com/content/journals/10.3897/jel..e47036https://www.aup-online.com/content/journals/10.5117/JEL.2020.1.47036Priya’s comment:
Typically when a fast track article is promoted to being part of an issue through a supply of the issue content zip file, the article is automatically moved from the fast track listing into the issue based on the DOI being the same for the fast track and issue-based versions. However in the above case, since the DOIs provided in the source XML are different for the two versions, you will see that the fast track article has been assigned a different DOI as compared to the eventual issue-based article and so the fast track article has not been moved automatically. Both DOIs have been already registered with Crossref so I think to resolve the duplication, you will need to first get one DOI to alias to the other in Crossref and then resolve the duplicate in the site, presumably by deleting the fast track version.