Huh. I did not know readability could be quantified.

But is can be. By the Gunning Fog Index.

Wiki:

In linguistics, the Gunning fog index is a test designed to measure the readability of a sample of English writing. The resulting number is an indication of the number of years of formal education that a person requires in order to easily understand the text on the first reading. That is, if a passage has a fog index of 12, it has the reading level of a U.S. high school senior. The test was developed by Robert Gunning, an American businessman, in 1952.[1]
The fog index is generally used by people who want their writing to be read easily by a large segment of the population. Texts that are designed for a wide audience generally require a fog index of less than 12. For texts that require a close to universal understanding generally requires an index less than 8.

So there you go. Technical and academic writing must assume a certain readership though, I presume. By this I don't mean to infer that writing of this kind necessarily assumes a certain level of literacy or intelligence, but that jargon and terminology may be an inevitability for clarity's sake, and would surely affect the level of readability by this scale.

And just for kicks, the unwitting winner of 'Philosophy and Literature' Bad Writing Contest, from Judith Butler, UC Berkley.

"The move from a structuralist account in which capital is understood to structure social relations in relatively homologous ways to a view of hegemony in which power relations are subject to repetition, convergence, and rearticulation brought the question of tempo­rality into the thinking of structure, and marked a shift from a form of Althus­serian theory that takes [End of page 354] structural totalities as theoretical objects to one in which the insights into the contingent possibility of structure inaugurate a renewed conception of hege­mony as bound up with the contingent sites and strategies of the rearticulation of power."

Fog Index rating of 74.*

*So says I.