Was made aware of this report from today's blog from A Cultered Left Foot.
http://www.aclfarsenal.co.uk/
The report is written by KEA - European Affairs, and CDES - The centre for the law and economics of sport. Basically, it is a report for the European Commission and it was published in January 2013. It is brand new in other words.
http://www.keanet.eu/docs/full_study_transferofplayers.pdf
This is a 345 page document and I was sure as hell never interested in reading the whole thing, but the Executive Summary is well worth a read for several reasons. What should catch everyone's attention is this bit, from the "Conclusions and Recommendations" part;
"Limit excesses in transfer fees after contract extension. Such limit aims to
avoid the possibility for clubs to extend the protected period with a view to trigger the payment of transfer fees. The system could provide for the transfer fee to be capped at 70% of the gross salary owed by the club to the player for the entire period of his contract."
A Cultured Left Foot put it into an Arsenal context;
"To put that into an Arsenal context, Robin van Persie would have cost Manchester United approximately £3.5m in the summer compared to the fee agreed between the two clubs."
Perhaps football is soon in for another change, and it could have every bit as much impact on the game as the Bosman ruling had.