Originally Posted by Often1

These are business-heavy routes where time is money. The prospect of driving is out of the question and the airfare is largely irrelevant. Carriers have also adjusted frequencies and aircraft to match the PRASM they need. The days when a carrier would simply drop prices until demand came up are over. Just try calling TW or NW to book !

Short-haul business center-to-business center is highly profitable and offsets lower fares on less competetive routes.

Just look at loads on routine flights and you will see that increasing the fare by $100 or more does not mean any significant difference in traffic. Thus, higher PRASM.