Apparently, for a quarter of all posts the skills of a co-worker does not match the requirements of the post; so OECD statistics. The mismatch differs among European Countries; by about factor two. The variations looks much like random fluctuations and bias compared a typical value. Considering the range of possible causes to accept an underqualified employee or to accept a less qualified job, 75% match does not look bad.
Source: Are we getting it right? The importance of assessing and anticipating skill needs
Ukko Elhob's World 