“70–85% of jobs are never publicly advertised.”

Attempts to trace the figure end at articles citing articles. Where a body such as a labour department is named, no dataset, table or publication is identified that we could check.

The number is quoted as anything from 70% to 85% depending on the page, with no explanation of the variation. A genuine measurement would have a source, a date and a population, and would not drift by fifteen percentage points between retellings.

The concept is entangled with the networking claim: both are used to argue that applying to advertised roles is a poor use of time, and each is frequently offered as evidence for the other.

Measuring this properly is hard in a way that is worth stating. It would require a representative sample of filled positions and a consistent definition of 'advertised', and we found no published attempt to do it.

A range this wide, quoted this confidently, for this long, without a citation, is the signature of a figure that was never measured. We treat the width of the range as evidence about the claim's provenance rather than as a legitimate uncertainty interval.

The honest version is that some hiring happens through channels a job seeker cannot see, that nobody has credibly quantified how much, and that this is a reason to diversify effort rather than to abandon applying.