Effect of Long-Tail Keyword Rank on Shorter KWs within that Phrase?

(Theoretical example): Let’s say I do some good SEO and keyword improvements on a long-tail keyword phrase like Long Sleeve Men’s Shirts and get a search engine ranking boost for that phrase. Will that also give a ranking boost to a shorter KW phrase within it — in this case, Men’s Shirts?

I know many of us have opinions on this, but does anyone know of any credible research on the effect that the rising rank of long-tail...

Effect of Long-Tail Keyword Rank on Shorter KWs within that Phrase?