Ok, so it’s a two part question.
How much wealth do they have? I hear they have substantial land holdings and I’m sure the buildings they have are very valuable as well. If for some reason they had to liquidate all their assets in this country how much would they be worth?
Second question is what is the annual income they make from donations?
That’s a bit of a difficult question, because there isn’t really a single “Catholic Church” entity that owns everything. I believe the individual dioceses are the direct owner of the churches and related land in their areas - there are 195 dioceses, so that’s 195 different “owners” there. In addition, many Catholic institutions (schools, colleges, hospitals) are owned by religious orders - Sister of Mercy, Jesuits, etc. Add Catholic Charities (which are often chartered separately so they can receive government funding) and some of the lay societies (like the Knights of Columbus), and you’re probably looking at at least a thousand different “Catholic” entities that that have only partial financial connections to each other.
Here in the Archdiocese of St. Louis, most of the wealth is in land and property. They recently closed a bunch of schools and put them on the market (the site has been archived, and I’m not going to pay to find it.) A lot of them were being offered at less than prime prices, and had been on the market for more time than you might think.
I’d guess a forced liquidation wouldn’t bring nearly as much as one might assume.
As for donations, I can’t hazard a guess. But a friend of mine who was heavily involved with the Episcopalians told me that all but two congregations in eastern Missouri were in some degree of deficit spending – which is pretty much my own experience with the churches I’ve been a member of.