How long, by word count, is the typical opera libretto?  If I were
going to write a libretto, how much would I have to write?  I'm
looking for an average here.  Take, let's say, Puccini, Verdi, and
Mozart together as "typical."  Or compose your own mix.

Bonus points for a breakdown into recitatives, arias, and choruses.  

Thank you,
Apteryx

This is just a guess .... 15,000 words.

Hi, Apteryx

Please include a part for a handsome baritone in full-dress uniform of
an officer in the 10th Royal Hussars (my old Regiment).

And, yes, I am your man!

Howdy, Apteryx.

This isn't an answer, but I thought you might find the material on
this page interesting:

http://www.davidscottmarley.net/personal/biblio.html

~Pink

Another article that's worth reading:

http://music.acu.edu/www/iawm/articles/june97/garwood.html

Your finds are always illuminating, Pink.  Thank you!  From the Marley article:

"Nobody would dream of trying to build a bridge or fly a plane without
first having had a considerable amount of study and experience. This
is due to a matter of personal safety that is of major concern.
However, there is no village in the United States in which there is
not at least one person dreaming the impossible dream, who does not
write a complete musical libretto that is most often replete with
tunes and lyric copyrights. These 'shows' are then dispatched in
envelopes covered with postage stamps to people like me."

That's a humbling thought and certainly echoes my sentiments about
people who think they can write; after all, they are language users as
much as the next person, are they not?  However, the people who do
this successfully must come from some village.  Why not mine?

Bryan, I love the image of you in a smart blue uniform lustily voicing
the musical utterances of the tenor's best friend.  Thank you kindly
for the offer.  I'm afraid the role doesn't quite fit the scenario I
have in mind, but I will consider it for future purposes.

Meanwhile, 15,000 seems high to me, especially considering that there
is likely to be a certain amount of repetition.  I would have guessed
somewhere nearer 3000, maybe not that much.  Anyone know a good way to
tell without seeking out libretti and counting?

Apteryx

Ok, I thought of a way myself.  I came up with about 3400 words in the
first act of La Boheme, about 3800 in the second, about 2000 in the
third, and about 2700 in the fourth.  That includes scene setting,
character names, and stage directions, in Italian, so in English it
would be more.  Total is 11,900.  Call it 12,000.  Even if a third of
that is not the actual libretto, Bryan, I'd say you were much closer
than I was.  Intuitively I would guess that a Verdi is wordier than a
Puccini.  That will do for my purposes, and I may as well close the
question.

Thank you,
Apteryx