Limit foreigners in sports leagues

I have always found it difficult to root for the local sports teams knowing that very few of their players are actually locals. In professional sports, teams carry the name of a location only because this is where they happen to play half their games, or possibly because management is local, but certainly not because of the players. In fact, I have always been in favor of some rule that would force teams to have at least some local content, so that local residents can better identify with these teams: "the players are from us."

It turns out that there can be economic reasons to do so beyond local loyalty. Markus Lang, Alexander Rathke and Marco Runkel show that imposing such constraints provides for more parity in a sports league, provides more profits to leagues and local players are better paid. But such constraints need to be imposed, as teams always want to deviate from such constraints. Similar constraints have been imposed in European football, apparently with success.