The Myth of the English Premium?
http://www.soccerbythenumbers.com/2012/11/the-myth-of-english-premium.html
"...when we put it all together, the numbers tell a clear story: British players go for less. Why, then, does the notion of a British premium still have legs?"
JK -- but see earlier posts on this thread about that article. In particular the point that the article uses transfermkt valuations of players, not the actual price paid. Home grown players have lower valuations on transfermkt, but if you want to actually sign Jordan Rhodes, or Ashley Williams, or whoever, you will undoubtedly pay a premium (compare the fee we agreed for Alderweireld with what would persuade Swansea to let Williams go). 
Not easy! Having started this particular thread though, I do try to keep abreast of it.
) -- here is a bit of fun from the statisticians at