In April 2008, the FAS (Fedora Account System) process was converted to a click-through process instead of a manual process of GPG signing and fax/email.
IMO CLA and all similar abbreviations: too much of a hassle to have to sign stuff. Came across above (though old) image and it seems to suggest that others feel the same.
So, all the new accounts increased code contributions to Fedora by a 10x magnitude.
Is that what you mean?
You see a sharp increase in the number of accounts once you did not have to use GPG+email/fax. As you could use email, I guess it is just about the hassle. It is somewhat difficult to determine if it aligns exactly, but there seems to be a strong correlation.
I rather prefer the approach of Linux and the DCO (Digital Certificate of Origin, see #11 in the link), which is not exactly the same, but it goes in the same direction (there was an addendum later.
FWIW, that is the meaning of sign-off.
It is very important to note that the Fedora Account System is not strictly mapped to functional code as shipped in Fedora packages.
For example, FAS accounts can be used to track membership in different self-governance subgroups for use in that groups internal governance. For example, you have to be an active member of the Ambassadors group to vote for the leadership in that group. This is tracked via the FAS system. In fact if you look at the group list all the groups listed as “tracking” are probably used in some way for membership rights not associated strictly with access to the packaging work.
To make more sense of the trend, and figure out what type of contribution the older need-to-sign CLA was holding back, you’d need to break out the trending of some of the individual groups. packagers,website,ambassador would be a salient first set to examine.
-jef