What Data Does Facebook Collect When I’m Not Using Facebook, and Why?

Re:What Data Does Facebook Collect When I’m Not Using Facebo... by JumpCrisscross on Monday April 16, 2018 @05:59PM (#16853228)

> There was a time when anti monopoly laws were taken seriously

Over the past century, economists came up with a measure of firm concentration called the HH Index [1]. The HH Index is "the sum of the squares of the market shares of the firms within the industry (sometimes limited to the 50 largest firms)". (It's derived from the Simpson ecological diversity index.)

Market share is a measure on customers. The DoJ used the HH Index to measure monopolies because monopoly power was understood to result from excessive market share. The case of non-paying consumers was never legally considered.

TL; DR More than apathy explains the delays in bringing antitrust action against Facebook.

[1] https://en.wikipedia.org/wiki/Herfindahl_index

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Re:What Data Does Facebook Collect When I’m Not Using Facebo... by chestervonwinch on Tuesday April 17, 2018 @07:44AM (#16857403)

> The case of non-paying consumers was never legally considered.

Is there an already-available analogous quantity to market share here? Or do you have thoughts about what might be used?

BTW, it's interesting that the HH index uses sum of squares to measure concentration of the distribution, where something like the Shannon entropy seems more natural -- although, "seems more natural" is subjective I suppose.

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