When editing a wav file in Audacity or Adobe Audition (or ProTools),
does the act of saving the edited file back to a wav cause any
degradation in the quality of the file? Is the saved file identical to
the original except for the editing changes?

Hi, 

This depends on the settings you have in your Preference area (in
Audacity... I'm sure the other is very similar). With Audacity open,
go to File->Preferences and you will be presented with the a Tab
Screen. Choose the "Quality" tab, and check your settings. If they are
the same as the file you opened, then yes, if they are not, then, no.

It is always best to have the program set at the same quality of the
file you are editing. Raising the program's quality above the file's
quality will not always produce desired effects. When editing keep the
quality the same, and then if you wish, experiement with different
settings using copies of your completed file.

thanks, 

webadept-ga