Separation of Academia and Private Sector

The "Peace Bridge" in Kashmir started me thinking about networks and separation. Here is the border between India and Pakistan, at least an interim one, which hasn't seen any interaction in 50 years. Interaction, or the lack thereof, is important. Biologists say that the definition of a species is reproduction across group lines. Getting back to my recent obsession with the causes of the presumed liberal dominance of academia, what sort of interaction do academics and the private sector have?

Because I've no data, and haven't been on campus for 40 years, the following is speculation:

• Humanities: English professors probably have very little. I can't think of a reason for them to do business with the world of business. The visual arts may have more--contact with art galleries, appraisals, and such. History (if you count it as a humanity), very little. The occasional expert witness in a lawsuit (I maintain membership in two historical groups, and vaguely remember something), writing company histories, etc.
• Area studies: things like black history, gender studies, American studies, etc. would be similar to humanities, although the opportunity for "talking heads" on TV is greater.
  
• Social sciences: probably more than humanities, a minority of professors could be consultants, do work within private companies, organizations, consulting, etc. Economists might be most linked.
  
• Physical sciences, including life sciences: the most interaction.
• New fields: things like IT, management, etc. probably have the most--indeed, my impression is there's a regular revolving door in IT.
  

If there's any validity to the above, there might be a correlation between interaction and conservatism--the more interaction the more conservative the academic specialty. Given the lack of interaction, maybe it's no surprise academia and the private sector seem to separate worlds--they are. I suspect though they're still capable of reproducing across group lines.