Southwest v Alaska, pt 2

Round-trip to San Jose this weekend:
Lowest fare: $290 SW, $312 AS
Fully refundable: $300 SW, $372 AS

I can see where you'd pick Alaska if you were hung up on frequent-flier miles and advance seat assignment (and unaware of what's going on with them flying out of Seatac).

21st-22nd
Lowest fare: $238 SW, $258 AS
Fully refundable: $300 SW, $372 AS

...

Feb 11-12
Lowest fare: $158 SW, $183 AS
Fully refundable: $300 SW, $317 AS

Two reactions:
I'm surprised that SW is actually less competitive as date-of-travel approaches. I'd have thought Alaska would really squeeze those travelers and SW would have a huge cost advantage, but it's not showing up. But it actually looks like you have to get further out, where Southwest's crazy internet-only specials are available, before they start to beat Alaska on price.

Alaska's cost to operate a flight is so much higher than Southwest's I don't understand how this is possible. I wonder how the two evolved in pricing to compete on this route, and why each is where they are. Also, I wish I could look up what their loads are... baffling.