So the Captain of an aeroplane isn't paid, amongst other things, to make "economic decisions"?
When do you have the CA of an aircraft deciding whom to purchase fuel from, which airport to serve when multiple airport are available, whom to contract for loading the aircraft, obtaining overflight permits, doing the actual flight planning (at your average airline anyway), arranging accommodation, setting prices etc. etc. etc.
Which airline expects this of their CAs?
If you're talking about speeds, obtaining better routing once en route and general management of the flight then this falls under the responsibility he has to operate the flight. The company still decides whether or not they want to operate a particular flight.
I'd love to see you get in an aircraft and decide to start serving Oslo from Nairobi without consulting the people who own/manage the place because you, as Captain, are making your own "economic decision".