24. If certain landed estates impede the general prosperity because they are extensive, unused or poorly used, or because they bring hardship to peoples or are detrimental to the interests of the country, the common good sometimes demands their expropriation.
Vatican II affirms this emphatically. (24) At the same time it clearly teaches that income thus derived is not for man’s capricious use, and that the exclusive pursuit of personal gain is prohibited. Consequently, it is not permissible for citizens who have garnered sizeable income from the resources and activities of their own nation to deposit a large portion of their income in foreign countries for the sake of their own private gain alone, taking no account of their country’s interests; in doing this, they clearly wrong their country. (25)
-From Populorum Progressio