Mater et Magistra §123

¹²³ First, with regard to agriculture, it would not appear that the rural population as a whole is decreasing, but it is an undeniable fact that many people are moving away from their farms into more thickly populated areas as well as into the cities themselves. When we realize that this movement of population is going on in nearly every part of the world, often on a large scale, we begin to appreciate the complexity of the human problems involved and their difficulty of solution.