[Gdh_lowq2] Stupid question: non-zero GDH for electron?

[adhikari at jlab.org]

Dear GDH followers,
Can we say an electron also has a non-zero GDH sum?

It's now known that an electron or a muon also have anomalous magnetic
moment due to quantum/radiative effects.
(https://en.wikipedia.org/wiki/Anomalous_magnetic_dipole_moment)

That means, the anomalies in magnetic moments have either of the following
two distinct origins:

1) Due to a substructure (i.e., due to being a composite object made up of
other particles) giving rise to huge anomalies such as that of a proton, a
neutron or a nucleus.
2) Due to quantum/radiative effects, giving rise to small anomaly (such as
that of an electron or a muon)

Because I have not heard or read anyone talking about GDH for an electron
or for any other similar particle, my hunch is that GDH sum rule perhaps
is associated only with the first part/kind of anomalous moment and not
with the other kind because the sum would have to be done over the excited
states which doesn’t exist in the latter case (no excited state of
electrons because it has no intrinsic structure of its own? Or can we
assume it to have some structure and finite size (form factor) due to the
virtual photon cloud that it may have as a result of the radiative/quantum
effects). But I have no idea if the sum rule is applicable for any
non-zero anomalous moment, no matter how the anomaly originated.

What would you think? Can we say that an electron should also have a non
zero GDH sum because it has a small but non-zero anomalous moment? It
would be great if somebody enlightens me on this.

Thank you.
Krishna