You can't trust grades, and can't trust letters of recommendation, so what can you trust?

There is an hidden disadvantage for students here. A-B-C-D-F grades have become nearly useless as entry gauges for many professions (the article emphasizes nursing and education). That means that employers have to lean more and more on other indicators. Letters of recommendation are more inflated than grades, so they don't help. That brings us to tangible things like internships, standardized test scores, and interviews.

Oh and intangibles. Like nepotism.

From John Hawk's paleoanthropology weblog, discussing grade inflation.

Personally this paragraph hits home for two reasons:

1. Having both written and read Astronomy job-related letters of recommendation I certainly think there is a huge variance in their accuracy and honesty, yet they seem to be given greater weight than objective publication records and citation counts. Possibly a majority are semi-accurate, but there is a sizable minority that are hyped out of all resemblance to reality (some I have read you might are laughable or must be jokes, except the joke is on the rest of us when those candidates get the nice jobs). The sad fact of the matter is that given that the number of higher level astro jobs available is always smaller than the number of qualified applicants such inflated letters of recommendation do often appear to work... at least in the cases where I have read seemingly hyped letters of recommendation for a candidate, and later investigate their papers and follow their career progression.
   
2. Having just had to look into what my high school grades were for the first time in almost twenty years I was very annoyed to also find that GCSE's and A-levels (this was the UK) have suffered monotonic grade inflation for approximately the last 30 years. What were pretty damn good grades for the time now seem average. And its not just that schools are better at teaching to slowly varying exams (or that students are smarter - hah!)... they're now giving out C grades in GCSE science if get only 18% of the questions right and A* grades if you get 51%.
   

[GPA grade inflation graph from Harold Marcuse (UC Santa Barbara)]