[Doctor Stochastic]

There is no concept of the "same" electron. Any two electrons (they can be counted) may be exchanged with no change in observables (the wave function changes sign though.) This can be shown by studying the statistics of electons (Fermi-Dirac.) Thus the question cannot be answered because no experiment (real or imagined) can tell if two appearences of an electron are the "same" electron.

Electrons have no internal labels.

[js1138]

Didn't someone once quip, "There is only one electron"?

[Qwinn]

I honestly don't know the precise details of how the notion of piggy-backing across electrons was discredited... I have absolutely no idea what words I could use to google-search for it, heh. I'm not up enough on the necessary terminology. I may know someone who knows the source though, I'll ask 'em and see if they can provide me with the docs.

Qwinn