"By observing returning visitors, we estimate how rapidly browser fingerprints might change over time. In our sample, fingerprints changed quite rapidly, but even a simple heuristic was usually able to guess when a fingerprint was an 'upgraded' version of a previously observed browser's fingerprint, with 99.1% of guesses correct and a false positive rate of only 0.86%"
https://panopticlick.eff.org/browser-uniqueness.pdf
From the paper:
"By observing returning visitors, we estimate how rapidly browser fingerprints might change over time. In our sample, fingerprints changed quite rapidly, but even a simple heuristic was usually able to guess when a fingerprint was an 'upgraded' version of a previously observed browser's fingerprint, with 99.1% of guesses correct and a false positive rate of only 0.86%"