It turns out I was right - here's something from Ethica Politica that quotes Benedict XVI, writing while he was Cardinal prefect of the Congregation of the Doctrine of the Faith.
Nothing particularly new here. I missed it because it wasn't a papal document while he was pope, and so it didn't show up in my search of the Vatican website for "capitalism."
The writings of Cardinal Ratzinger appeared as a 1985 symposium titled, Church and Economy in Dialogue. It features other cardinals and a speech by John Paul II to the symposium participants.
You can find it here: http://ordosocialis.de/pdf/lroos/K%20u%20W%20in%20Dialog/dialoenga4neu.pdf
It is worth reading by anyone who wants clarity as to whether the Church supports any particular economic theory. In short: Without the participants in an economy acting morally - with virtue and ethical standards that consider the big picture of "we're all human beings and we're all in this together" - ANY economic system will be fraught with injustice and exploitation.
And that is the common thread of magisterial texts on the subject, and with which Pope Francis is very much in line.