Questions we could not answer, so we measured.
Every study here starts with an argument we kept having with a client and could not settle from opinion. We run the numbers on the accounts we manage, publish the method, and publish the parts where the answer was no.
We ran both rank trackers on the same keywords for two weeks, plus DataDive on one brand. They agree on who ranks, on the top 10 and on trends. Further down the exact positions differ, even when they check at the same moment, and the differences go both ways.

Daily bids, placement modifiers and realized CPC per placement on exact-match branded campaigns. Top of Search costs half the product-page click because brands pay 11% of their bid there and 88% on product pages. The modifier buys share, not price.

We matched daily organic rank against Search Query Performance across six US consumer brands, week by week. Impression share identifies the rank band reliably. It cannot see week-to-week movement.

Including the parts that did not work.
A study that only reports what confirmed the hypothesis is marketing. The SQP paper's most useful finding is a failure: subtracting ad impressions to clean the signal made the proxy measurably worse. The branded CPC paper spends a full section on the days where its own effective-bid math breaks.
Got a question worth measuring?
Most of these studies started as a client asking something we could not answer honestly. If you have one, send it over. It might become the next paper.