Sheep fancier,
You can download the latest Annual report here
http://www.baa.com/main/corporate/in...ons_frame.html
Look at segmental analysis, which comes just after the accounts as a note. You will see a breakdown of the numbers by airport.
Return on capital employed (ROCE) is a key measure of the profitability of an enterprise. It basically measures how much profit is made relative to how much is invested to make that profit and is normally used by management to decide where to invest more of the company's capital.
The point I made earlier was that right now ROCE is exactly the same at GLA and EDI. However adding the substantial capital cost of a new tower at EDI would alter that.
It would appear though that politics will play a bigger part in future expansion than economics.
Gusty