I am writing an academic essay (APA standard) in which I compare a lot of proportions (and probability estimations).
Phrases like
... are 5.2 percentage points more likely to ...
are common. So I want to use an abbreviation. But not sure if to use pps, PPs, pp, PPt, or just pp. Curiously, I find nothing from APA or anyone else when doing a quick web search looking for best practices. At this point any insights or standard I can follow is good enough.
Update
Percentage point is different from a percent (literally part of a hundred).
Example:
30 percent of customers complained about our service last year. This year only 24 percent.
So we would say there has been 6 percentage points decrease in complaint but the decrease is also 0.06/0.30 = 0.2 = 20 percent.