I don't think the curse applies specifically to the driver who finishes 2nd in points as much as it belongs to the driver that had the chance to win the title in the final race and came up short.
Also, it's not a curse, it's a team-wide loss of morale, caused by a heart-wrenching championship loss when your season-long goal that seemed attainable is taken away at the last possible minute.
Going into Homestead in 2010, Denny Hamlin lost the title to Jimmie Johnson, and that loss sent his team into a tailspin the following season, and even resulted in a change of crew chiefs at the end of 2011 for a team that had won 8 races in 2010.
In 2011, it was Carl Edwards losing the title on a tie-breaker to Tony Stewart. The giant loss in morale sent the 99 team in to the tank for the entire 2012 season, even when his Roush Ford teammates Kenseth and Biffle were soaring.
Yesterday, the battle for the championship was between only two teams, the 2 and the 48 team. The 2 won the Cup, and the 48 lost in an ugly fashion, completely collapsing over the final two races to give it away. To me, "the curse" would appear to belong to the 48, despite the fact that the 15 team passed them by a point at the end of the day for second place. If any team is going to be in the dumps because of giving away a chance to win the title, it's not the 15 team.
Sigh...
It drives me nuts when people act as though they understand the psychology of people they've never met. Why should it be any less plausible, for example, that a team would be "fired up" and extra motivated for the following season by coming so close that they could taste it? Even if we took for granted that there really was a loss of morale, it's a long offseason for emotions to subside, and at any rate, there are vastly more psychological factors at work than just "feeling deflated." People's motivations and insecurities are complicated - surely you know that based on the people you're close to.
Plus, it's very unclear to me how a "loss of morale" would lead to a performance the next season that was worse across the board. Under your hypothesis, then, would the wind tunnel guys be too despondent to put as much effort into their work? Would the shock specialist be haunted by memories of what went wrong in the season finale and nervously throw a totally different setup on it for fear that the same thing will happen again? Would the driver or crew chief be totally psyched out and unable to make the correct decisions on and off the track? I just don't see any plausible way for a "loss of morale" to translate into a big performance drop.
There's a much simpler way to explain the supposed effect: reversion to the mean. Teams that finish at or near the top of the point standings will have, on average, overperformed their "true talent." Maybe they randomly hit on a perfect setup a couple of times, got bitten by pit strategy a couple fewer times while having it play right into their hands a couple more times, had no engine failures all season, got caught up in only one accident not of their own making, etc. But, on average, these teams will have neutral luck the following season, so it will look like a performance dropoff even when their "luck-adjusted performance" has been just as good. My hypothesis should apply to all drivers at the top of the standings, not just the runner-up, so let's examine the historical record, beginning with the first year of the Chase for comparability's sake, to see what happened to the top three drivers the season after:
2004:
1. Kurt Busch -> 10th
2. Jimmie Johnson -> 5th
3. Jeff Gordon -> 11th
2005:
1. Tony Stewart -> 11th
2. Greg Biffle -> 13th
3. Carl Edwards -> 12th
2006:
1. Jimmie Johnson -> 1st
2. Matt Kenseth -> 4th
3. Denny Hamlin -> 12th
2007:
1. Jimmie Johnson -> 1st
2. Jeff Gordon -> 7th
3. Clint Bowyer -> 5th
2008:
1. Jimmie Johnson -> 1st
2. Carl Edwards -> 11th
3. Greg Biffle -> 7th
2009:
1. Jimmie Johnson -> 1st
2. Mark Martin -> 13th
3. Jeff Gordon -> 9th
2010:
1. Jimmie Johnson -> 6th
2. Denny Hamlin -> 9th
3. Kevin Harvick -> 3rd
2011:
1. Tony Stewart -> 9th
2. Carl Edwards -> 15th
3. Kevin Harvick -> 8th
The average dropoff from 1st place is four spots; from 2nd, 8.6 spots; and from 3rd, 6.4 spots. There's some support for the idea that second place is particularly affected, but I submit that it does not pass any test of statistical significance.
If, as you suggest, we only include drivers with a realistic shot to win in the final race,* their average finish the following year was 8.5 - but as I've already documented, this is perfectly normal for anyone near the top of the standings. As a control group - since this is a very scientific study
- I'll take all of the drivers in each season who finished fourth or better in the standings but
didn't have much of a chance heading into the final race.** These drivers averaged a finish of 8.9 in the following season, i.e. slightly worse than those who did have a shot to win. Now, it's true that because they were out of contention going into Homestead, these drivers generally were a little lower in the standings in the year of interest, so we would expect them to do a little worse the year after. But even if you make a correction for that, it's hard to see any big effect from "loss of morale." Mostly, teams that do well in one season will simply do worse in the following season. Simple as that.
*Johnson and Gordon in 2004; Edwards and
Johnson (damn, he must have been awfully deflated after falling from second to fifth in the final race!) in 2005; Kenseth, Harvick, and Hamlin in 2006; Gordon in 2007; nobody in 2008; Martin in 2009; Hamlin and Harvick in 2010; Edwards in 2011
**Martin in 2004; Biffle and Martin in 2005; nobody in 2006; Bowyer and Kenseth in 2007; Edwards, Biffle, and Harvick in 2008; Gordon and Kurt Busch in 2009; Edwards in 2010; Harvick and Kenseth in 2011