plc90210 - 11:07 pm on Apr 7, 2013 (gmt 0)
@TheOptimizationIdiot: No offense, but judging by your posts (not just in this thread), it's very hard to believe that you have ever built websites or done any sort of SEO work.
"but threads here for years with old sites tanking and new sites ranking say your theory is incorrect."
Those threads tend to not mention specifics about the ranking changes. There are lots of reasons that old sites can tank (i.e. Panda/Penguin updates, duplicate content, manual penalties, etc) and there are lots of reasons why new sites can rank high (i.e lack of keyword competitiveness).
Obviously, Google isn't going to be completely transparent about these type of things so it's not surprising that they haven't given out any specifics regarding domain age as a ranking factor.
I'm not sure if webmasterworld threads would be regarded as a "highly respected authoritative source", but here are a few (of many) threads that agree on domain age being a factor:
You can find many other sources with a quick Google search.
By the way, you had not given any citations from authoritative sources saying that domain age isn't a factor either (unless if you consider yourself a respected authoritative source) :P