A new report from Georgetown University's Center for Applied Research in the Apostolate shows some interesting, though perhaps unsurprising, data. Parishes in the U.S. are getting larger and fewer, with more attendance, collections and masses at each parish. This take on it raises the possibility that migration is causing the well-known parish closures in areas people are moving away from, but may not be causing enough parish openings in areas they're moving to.
One liturgical effect of this trend: more masses in each parish per weekend, averaging four. The ancient ideal of "one liturgy at one altar in one day" has long been a distant memory for Roman Catholics, but we seem to be moving away from the ideal, rather than moving toward it (I wonder if RCs would even buy into the ideal anyway, or any reasoning for it).
The full report is here.