. . . [F]irms import and export significantly more with countries that have a strong resident population near their firm headquarters location. . .
We show that one particular channel of the information network is through board members: a connected local population predicts more board members from that same country, and a significantly higher value for those firms that exploit connected board members in their trade decisions.
That is from the new paper by Umit, Gurun, and Malloy (August 2012) "Channels of Influence." The evidence is from the US.