Of course maybe Rick is wrong, but...
Bill left the best stat from Rick out of his post: the NFL is seeing its highest average viewing across all networks through this point in the season in twenty years. Twenty years! While this isn't data that confirms the speculation, it is at least data!
It's all speculative, and hell, it's not like we don't speculate ourselves frequently and whether Bill likes it or not, the speculation itself is reasonable. Compared to all the Obama Endorsement leads to bad news for Oprah's ratings, it's in the realm of downright respectable speculation. Football ratings are up (best averages in 20 years so far!) and the economy is bad.
Unfortunately, there is no "Sunday Sports Bar Sales During NFL Games By The Numbers" to turn to. It would perhaps provide the best indicator of the impact of the economy on measured TV ratings (sports bars aren't measured) for NFL games. Are there more people who live in Nielsen homes staying home to watch football rather than going to sports bars to watch? Perhaps, and perhaps not. Sadly, no data!
HDTV and big screen TVs may be a factor (completely independent of the economy)
What Rick cited as an effect may actually be part of the cause. People really like watching on their big screens in HD, and perhaps not just because it's the best value for the buck, but because it is a great experience. And I'm not just saying that because *I* like it. I've talked to a couple of networks and the data suggests (I've seen nothing conclusive) that the proliferation of HDTV has led to more time spent watching football. They have some stats on HD viewing, but so far I haven't been able to get my hands on them.
Combining the worst of both worlds, my rooting interest, The Washington Redskins blames both a bad economy and lack of compelling match ups as the reason some people aren't showing up for games, and fewer people are watching on TV locally. Of course the match ups aren't compelling. That's because the Redskins suck!