Thank you to everyone who responded to my question last week
regarding the binding of title changes.  I have received 21 responses
so far, and the results are as follows:

1.  Bind each title separately.  The clear winner, with 18 libraries
using this method.  Several people noted that if possible, the
partial volume of the preceding title is bound with the previous
volume; likewise, the partial volume of the succeeding title is
bound with the next volume.  This method was also mentioned as the
best way to avoid complications with automated circulation systems.
A couple of libraries are very specific on the spine numbering, for
example: v.49-50 no.5 1986-1987 for the old title; v.50 no.6-v.52
1987-1989 for the new title.  Another library is not so specific on
the spine numbering.  If the old title contains issues 1-4 and the
new title continues with issues 5-6, this is not indicated on the
spine.  Each title is considered complete in itself.  The same
library also reported that if the title change does not require a new
record, the new variant title (e.g. discussion re Polk, Polk's) is
the title that is printed on the spine even if the cataloging record
(245 tag) still shows the older title.

2.  Bind the entire volume as the new title (no matter what portion
of the volume is the new title).  One library uses this method.  They
also add a note that volume XX of the old title is bound with the new
title.

3.  Bind the entire volume with the old title on the spine and change
to the new title with the next full volume.  One library uses this
method.  They also include a "Bound with volume X" note on the
bibliographic records of both titles.