I am looking for an authoritative source for the standard methodology for decomposing growth between market and individual units.
For example, in retail sales, decomposing growth between market level and product level (e.g. if market grew 5% and product grew 7%, then 5% due to market and 2% due to product).
In the stock market, this would be analogous to the growth due to market vs due to individual stocks (e.g. stock price grew by 7% but market was up 5%, then 2% due to individual stock).
Some weak references like this are all I've been able to find, but seems it should be a common problem in things like technical analysis (I probably just don't know how to refer to it).