Hi Roger,

It's quite amazing how things are coming together.

Here is another piece of the puzzle.
Attached is a plot from the early blocking page I did. 
Look at the upper right plot.
The BLACK trace is the event analysis cumdev for the 1-sec standard analysis (aka netvar).

It's a bit hard to see, but it shows the cumulative result for all accepted events using the standard recipe.
The big downward kink between 85-125 corresponds exactly to the big drop in the overall netvar from Jan 2002 - Oct 2003.

[Detail: the plot is a little different than the usual z-score cumdev. It plots the terminal value of the aggregate result at each point.]

So all those events were effected by that persisent year(s)-long trend.
If we want to estimate post-hoc what's the real-time effect of the events, we need to take out the long-timescale background trend.
So clearly there is a stronger event effect happening than get from the the formal analysis result.

And, by the way, it appears that decrease effect goes away at larger blockings, just like the overall event effect. More evidence that the 1-sec netvar is our best stat.

-p