The person whose name appears on an article usually did not write the words above it. The division of labour is old, deliberate, and explains many complaints about coverage.
The headline was originally a layout problem
In print, a headline had to fit an exact column width in a chosen typeface, which meant counting characters and finding synonyms that fit the space.
Sub-editors specialised in that craft, working across many stories a night with an eye on the whole page rather than any single article.
Reporters, filing to deadline and close to their own material, were poorly placed to compress it into six words that fit a measured slot.
Distance from the material is an advantage
A reporter knows every qualification in the story and tends to write a headline that protects all of them, producing something accurate and unreadable.
An editor reading it cold sees what a stranger would take from it, which is closer to how the audience will actually encounter the piece.
That editor is also checking the article against the rest of the day's coverage, catching contradictions and repetition that the reporter cannot see from inside one story.
Online, the headline became a distribution tool
A digital headline must work as a search result, as a social card, in a newsletter and on the publication's own front page, each with different constraints.
Many outlets write two versions for this reason: a descriptive one containing the terms people search for, and a more conversational one for the page itself.
Testing formalised the split further, with variants shown to different segments of the audience and the better performer promoted automatically.
The incentives can pull away from the article
Attention is scarce, and a headline that overstates a finding will collect more of it than one that states the finding precisely.
The pressure is strongest where revenue depends on volume, and weakest where it depends on subscribers who cancel when they feel misled.
Complaints about sensationalism are therefore often complaints about the business model reaching the headline through the person writing it.
Responsibility is genuinely divided
Corrections policies usually cover headlines, and a headline that misrepresents an accurate article is treated as an error by the publication rather than the reporter.
Reporters frequently object publicly to headlines on their own work, which is confusing to readers who assume a single author.
Understanding that the byline and the headline come from different desks explains a great deal about how coverage is received and argued over.