The vast majority of Catholic parish and school closings are due to the fact that Catholics are moving out of these parishes. The problem is that many places where Catholics are moving to the Church has little or no presence, particularly here in the South.
I live in a small unincorporated town of about 15000 in South Carolina. The Catholics met at a school here for many years with about 300 attending. The diocese finally decided to build a church here two years ago that would seat 450. They thought it would give them room for future growth. Since it opened they have five Masses every week that are standing room only. By the diocese's own admission, they had no idea there were so many Catholics in the area.
The Catholic Church has done a poor job here in the US in dealing with a mobile society. 100 years ago they were fairly quick in moving into areas where Catholics moved into. But today they are reticent in closing old churches and schools where there are few Catholics and building new ones where the Catholics have emigrated.
As a result Protestant churches in the South are growing from the influx of Catholics that have no church home. About one quarter of our church are former Catholics.
The Boston Archdiocese has been attempting to close and/or merge Parishes for years with little success. It is an ongoing battle which will take years to solve.
It appears that many Catholics are "married" to their home Parish, not the Catholic Church.
Our diocese is building yet another Catholic high school. The new principal came to Mass last week, Campion - she’s one of your Nashville Dominicans. It was wonderful to see a young, joyful, habited sister. Private groups opened another Catholic-tradition high school a couple of years ago when the bishop was still undecided on where the diocesan one would be because their kids couldn’t wait for a Catholic education. I’m not sure how viable it will be once the diocesan one opens. The elementary school at our parish has set up so many temporary buildings that if I ever tried to cut through I’d need a ball of string.