Education credentials don’t so much demonstrate the holder has the requisite job skills. It’s more to signal conformity, intelligence, and a willingness to work hard. The idea that secondary schools and universities are pumping out job-ready prospects is a joke. We know this in multiple ways, and here are just three of them:

• First-hand experience: have you used your crappy GSCE French recently?
• The psychology of learning: economics students can’t apply economics outside the classroom.
• The sheepskin effect: why is finishing the last month of university education more valuable than every other month combined on the job market?

Why don’t people want to accept this? Partly they’re confused as to the claim. Signalling theory doesn’t state that none of the learning is applicable, nor does it rely on ability bias.

Some people likely resist the idea because education is too fundamental an institution to change. There will also be social pressure to say that more education is better, despite little reason to believe this in developed countries. The fields that provide supporting evidence for signalling theory, like social psychology and sociology, aren’t respected as much as “hard sciences”. The implications are scary; if you accept that 80% of why students with qualifications earn more is because they serve as a signal, you inevitably have to decide taxpayer money shouldn’t support it. Then there are the people who assume it must be there for a reason, so “shut up”.