Gary Taylor, a professor at Florida State University and the principal investigator of the new work, said Shakespeare had now "entered the world of Big Data".
"There are certain questions that we are now able to answer more confidently that people have been asking for a very long time."
Taylor said academics had known for a long time that Shakespeare worked with other writers on some plays. The idea that he collaborated with Marlowe on the Henry VI plays had been debated for centuries, but had not been possible to demonstrate before.
Taylor said scholars had used databases of plays and other writings by many artists working in the Elizabethan period to search for distinctive words or combinations of words.
"That kind of Big Data was never available until very recently."
The academics who worked on the New Oxford Shakespeare, and others who had provided peer reviews of their findings, were extremely confident about Marlowe's authorship of some parts of the Henry VI plays, Taylor said.
"There are parts that are very clearly by Shakespeare and there are parts ... very clearly by Marlowe."
The previous edition of Shakespeare's complete works by the same publisher, issued in 1986, identified eight of 39 plays as collaborative.
- staff reporter, agencies