Dirigo I don't personally have the data but I know in a friends industry where I shared data earlier they are seeing unprecedented shifts. The reason google is making many changes quickly isn't to give us headaches. They see the same data.
I see it manifesting in a continual rise of bing. I see erratic huge shifts in traffic.
Upstream at the supplier level there was an inverse relationship. When reseller traffic dove their traffic was up and vice versa. All related to google tweaks.
Google does have the power to hurt the economy and some of their actions and changes this fall no doubt have has this effect. They know this but how much do they really understand the algo at this point or is this becoming the earlier windows kernels where at some point the process needs to be started from line 1 again?
What people forget is how much etail effects regular commerce. Joe public may use google to check product a for price, availability, specs and then go buy it locally or if they can't find it at all assume it's no longer available. There were thousands of our skus that vanished from the SERPS and were replaced by nonsense. Every company selling these items was gone.
The thought that a few key searches by key players per google can effect traffic....can you say pay per search?